the future americans model: technical documentation · october 12, 2016 1. contents 1 functioning...
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The Future Americans Model: Technical Documentation
Dana P. Goldman, University of Southern CaliforniaDuncan Ermini Leaf, University of Southern California
Bryan Tysinger, University of Southern California
October 12, 2016
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Contents
1 Functioning of the dynamic model 31.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3 Comparison with other microsimulation models of health expenditures . . . . . . . . 4
1.3.1 CBOLT Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.3.2 Centers for Medicare and Medicaid Services . . . . . . . . . . . . . . . . . . 51.3.3 MINT Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Data sources used for estimation 62.1 Panel Survey of Income Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.2 Health and Retirement Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.3 Medical Expenditure Panel Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.4 Medicare Current Beneficiary Survey . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3 Estimation 73.1 Transition model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1.1 Further Details on Specific Transition Models . . . . . . . . . . . . . . . . . 93.1.2 Inverse Hyperbolic Sine Transformation . . . . . . . . . . . . . . . . . . . . . 10
4 Model for replenishing cohorts 104.1 Model and estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.2 Trends for replenishing cohorts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5 Government revenues and expenditures 115.1 Medical costs estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6 Implementation 136.1 Intervention Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7 Validation 147.1 Cross-validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
7.1.1 Demographics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147.1.2 Health Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157.1.3 Health Risk Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157.1.4 Economic Outcomes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
7.2 External Corroboration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
8 Baseline Forecasts 158.1 Disease Prevalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9 Acknowledgments 17
10 Tables 18
References 33
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List of Figures
1 Architecture of the FAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Historic and Forecasted Chronic Disease Prevalence for Men 25+ . . . . . . . . . . 163 Historic and Forecasted Chronic Disease Prevalence for Women 25+ . . . . . . . . . 164 Historic and Forecasted ADL and IADL Prevalence for Men 25+ . . . . . . . . . . . 175 Historic and Forecasted ADL and IADL Prevalence for Women 25+ . . . . . . . . . 17
List of Tables
1 Estimated outcomes in replenishing cohorts module . . . . . . . . . . . . . . . . . . 182 Estimated outcomes in transitions module . . . . . . . . . . . . . . . . . . . . . . . 193 Health condition prevalences in survey data . . . . . . . . . . . . . . . . . . . . . . 204 Survey questions used to determine health conditions . . . . . . . . . . . . . . . . . 215 Outcomes in the transition model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 Restrictions on transition model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 Descriptive statistics for stock population . . . . . . . . . . . . . . . . . . . . . . . . 248 Parameter estimates for latent model: conditional means and thresholds . . . . . . . 259 Parameter estimates for latent model: parameterized covariance matrix . . . . . . . 2610 Health and risk factor trends for replenishing cohorts, prevalences relative to 2009 . 2711 Education trends for replenishing cohorts, prevalences relative to 2009 . . . . . . . . 2812 Social trends for replenishing cohorts, prevalences relative to 2009 . . . . . . . . . . 2913 Crossvalidation of 1999 cohort: Mortality in 2001, 2007, and 2013 . . . . . . . . . . 3014 Crossvalidation of 1999 cohort: Demographic outcomes in 2001, 2007, and 2013 . . 3015 Crossvalidation of 1999 cohort: Binary health outcomes in 2001, 2007, and 2013 . . 3016 Crossvalidation of 1999 cohort: Risk factor outcomes in 2001, 2007, and 2013 . . . . 3117 Crossvalidation of 1999 cohort: Binary economic outcomes in 2001, 2007, and 2013 . 3118 Population forecasts: Census compared to FAM . . . . . . . . . . . . . . . . . . . . 32
1 Functioning of the dynamic model
1.1 Background
The Future Elderly Model (FEM) is a microsimulation model originally developed out of an effortto examine health and health care costs among the elderly Medicare population (age 65+). Adescription of the previous incarnation of the model can be found in Goldman et al. (2004). Theoriginal work was founded by the Centers for Medicare and Medicaid Services and carried out bya team of researchers composed of Dana P. Goldman, Paul G. Shekelle, Jayanta Bhattacharya,Michael Hurd, Geoffrey F. Joyce, Darius N. Lakdawalla, Dawn H. Matsui, Sydne J. Newberry,Constantijn W. A. Panis and Baoping Shang.
Since then various extensions have been implemented to the original model. The most recentversion of the FEM now projects health outcomes for all Americans aged 51 and older and uses theHealth and Retirement Study (HRS) as a host dataset rather than the Medicare Current BeneficiarySurvey (MCBS). The work has also been extended to include economic outcomes such as earnings,labor force participation and pensions. This work was funded by the National Institute on Agingthrough its support of the RAND Roybal Center for Health Policy Simulation (P30AG024968),
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the Department of Labor through contract J-9-P-2-0033, the National Institutes of Aging throughthe R01 grant “Integrated Retirement Modeling” (R01AG030824) and the MacArthur FoundationResearch Network on an Aging Society.
This document describes the Future Americans Model (FAM), the development of the model toforecast Americans aged 25 and older. FAM uses the Panel Survey of Income Dynamics (PSID) asthe host dataset. In addition to modeling health, health care costs, and economic outcomes, FAMalso models life events such as changes in marital status and childbearing. Development of FAMis suported by the National Institutes of Aging through the USC Roybal Center for Health PolicySimulation (5P30AG024968-13) and the MacArthur Foundation Research Network on an AgingSociety.
1.2 Overview
The defining characteristic of the model is the modeling of real rather than synthetic cohorts, allof whom are followed at the individual level. This allows for more heterogeneity in behavior thanwould be allowed by a cell-based approach. Also, since the PSID interviews both respondent andspouse, we can link records to calculate household-level outcomes, which depend on the responsesof both spouses.
The model has three core components:
• The replenishing cohort module predicts the economic and health outcomes of new cohortsof 25/26 year-olds. This module takes in data from the Panel Survey of Income Dynamics(PSID) and trends calculated from other sources. It allows us to generate cohorts as thesimulation proceeds, so that we can measure outcomes for the age 25+ population in anygiven year.
• The transition module calculates the probabilities of transiting across various health statesand financial outcomes. The module takes as inputs risk factors such as smoking, weight, ageand education, along with lagged health and financial states. This allows for a great deal ofheterogeneity and fairly general feedback effects. The transition probabilities are estimatedfrom the longitudinal data in the PSID.
• The policy outcomes module aggregates projections of individual-level outcomes into policyoutcomes such as taxes, medical care costs, and disability benefits. This component takesaccount of public and private program rules to the extent allowed by the available outcomes.
Figure 1 provides a schematic overview of the model. In this example, we start in 2014 with aninitial population aged 25+ taken from the PSID. We then predict outcomes using our estimatedtransition probabilities (see section 3.1). Those who survive make it to the end of that year, atwhich point we calculate policy outcomes for the year. We then move to the following time period(two years later), when a replenishing cohort of 25 and 26 year-olds enters (see section 4). Thisentrance forms the new age 25+ population, which then proceeds through the transition model asbefore. This process is repeated until we reach the final year of the simulation.
1.3 Comparison with other microsimulation models of health expendi-tures
The precursor to the FAM, the FEM, was unique among models that make health expenditureprojections. It was the only model that projected health trends rather than health expenditures.
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Figure 1: Architecture of the FAM
It was also unique in generating mortality projections based on assumptions about health trendsrather than historical time series.
FAM extends FEM to younger ages, adding additional dimensions to the simulation. Eventsover the life course, such as marital status and childbearing are simulated. Labor force participationis modeled in greater detail, distinguishing between out-of-labor force, unemployed, working part-time, and working full-time.
1.3.1 CBOLT Model
The Congressional Budget Office (CBO) uses time-series techniques to project health expendituregrowth in the short term and then makes an assumption on long-term growth. They use a long termgrowth of excess costs of 2.3 percentage points starting in 2020 for Medicare. They then assume areduction in excess cost growth in Medicare of 1.5% through 2083, leaving a rate of 0.9% in 2083.For non-Medicare spending they assume an annual decline of 4.5%, leading to an excess growthrate in 2083 of 0.1%.
1.3.2 Centers for Medicare and Medicaid Services
The Centers for Medicare and Medicaid Services (CMS) performs an extrapolation of medicalexpenditures over the first ten years, then computes a general equilibrium model for years 25through 75 and linearly interpolates to identify medical expenditures in years 11 through 24 of theirestimation. The core assumption they use is that excess growth of health expenditures will be onepercentage point higher per year for years 25-75 (that is if nominal GDP growth is 4%, health careexpenditure growth will be 5%).
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1.3.3 MINT Model
Modeling Income in the Near Term (MINT) is a microsimulation model developed by the UrbanInstitute and others for the Social Security Administration to enable policy analysis of proposedchanges to Social Security benefits and payroll taxes Smith and Favreault (2013). MINT uses theSurvey of Income and Program Participation (SIPP) as the base data and simulates a range ofoutcomes, with a focus on those that will impact Social Security. Recent extensions have includedhealth insurance coverage and out-of-pocket medical expenditures. Health enters MINT via self-reported health status and self-reported work limitations. MINT simulates marital status andfertility.
2 Data sources used for estimation
The Panel Survey of Income Dynamics is the main data source for the model. We estimate modelsfor assigning characteristics for the replacement cohorts in Replenishing Conditions Module. Theseare summarized in Table 1. We estimate transition models for the entire PSID population in theTransition Model Module. Transitioned outcomes are described in Table 2.
2.1 Panel Survey of Income Dynamics
The Panel Survey of Income Dynamics (PSID), waves 1999-2013 are used to estimate the transitionmodels. PSID interviews occur every two years. We create a dataset of respondents who haveformed their own households, either as single heads of households, cohabitating partners, or marriedpartners. These heads, wives, and ”wives” (males are automatically assigned head of householdstatus by the PSID if they are in a couple) respond to the richest set of PSID questions, includingthe health questions that are critical for our purposes.
We use all respondents age 25 and older. When appropriately weighted, the PSID is represen-tative of U.S. households. We also use the PSID as the host data for full population simulationsthat begin in 2009. Respondents age 25 and 26 are used as the basis for the synthetic cohorts thatwe generate, used for replenishing the sample in population simulations or as the basis of cohortscenarios.
The PSID continually adds new cohorts that are descendents (or new partners/spouses of de-scendents). Consequently, updating the simulation to include more recent data is straightforward.
2.2 Health and Retirement Study
The Health and Retirement Study (HRS), waves 1998-2012 are pooled with the PSID for estimationof mortality and widowhood models. The HRS has a similar structure to the PSID, with interviewsoccurring every two years. The HRS data is harmonized to the PSID for all relevant variables. Weuse the dataset created by RAND (RAND HRS, version O) as our basis for the analysis. We useall cohorts in the analysis. When appropriately weighted, the HRS in 2010 is representative of U.S.households where at least one member is at least 51. Compared to the PSID, the HRS includesmore older Hispanics and interviews more respondents once they have entered nursing homes.
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2.3 Medical Expenditure Panel Survey
The Medical Expenditure Panel Survey (MEPS), beginning in 1996, is a set of large-scale surveysof families and individuals, their medical providers (doctors, hospitals, pharmacies, etc.), and em-ployers across the United States. The Household Component (HC) of the MEPS provides datafrom individual households and their members, which is supplemented by data from their medicalproviders. The Household Component collects data from a representative sub sample of householdsdrawn from the previous year’s National Health Interview Survey (NHIS). Since NHIS does notinclude the institutionalized population, neither does MEPS: this implies that we can only usethe MEPS to estimate medical costs for the non-elderly (25-64) population. Information collectedduring household interviews include: demographic characteristics, health conditions, health status,use of medical services, sources of medical payments, and body weight and height. Each year thehousehold survey includes approximately 12,000 households or 34,000 individuals. Sample size forthose aged 25-64 is about 15,800 in each year. MEPS has comparable measures of social-economic(SES) variables as those in PSID, including age, race/ethnicity, educational level, census region,and marital status. We estimate expenditures and utilization using 2007-2010 data.
See Section 5.1 for a description. FAM also uses MEPS 2001-2003 data for QALY model esti-mation.
2.4 Medicare Current Beneficiary Survey
The Medicare Current Beneficiary Survey (MCBS) is a nationally representative sample of aged,disabled and institutionalized Medicare beneficiaries. The MCBS attempts to interview each re-spondent twelve times over three years, regardless of whether he or she resides in the community,a facility, or transitions between community and facility settings. The disabled (under 65 years ofage) and oldest-old (85 years of age or older) are over-sampled. The first round of interviewingwas conducted in 1991. Originally, the survey was a longitudinal sample with periodic supplementsand indefinite periods of participation. In 1994, the MCBS switched to a rotating panel designwith limited periods of participation. Each fall a new panel is introduced, with a target samplesize of 12,000 respondents and each summer a panel is retired. Institutionalized respondents areinterviewed by proxy. The MCBS contains comprehensive self-reported information on the healthstatus, health care use and expenditures, health insurance coverage, and socioeconomic and demo-graphic characteristics of the entire spectrum of Medicare beneficiaries. Medicare claims data forbeneficiaries enrolled in fee-for-service plans are also used to provide more accurate information onhealth care use and expenditures. MCBS years 2007-2010 are used for estimating medical cost andenrollment models. See section 5.1 for discussion.
3 Estimation
In this section we describe the approach used to estimate the transition model, the core of the FAM,and the initial cohort model which is used to rejuvenate the simulation population.
3.1 Transition model
We consider a large set of outcomes for which we model transitions. Table 5 gives the set of outcomesconsidered for the transition model along with descriptive statistics and the population at risk whenestimating the relationships.
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Since we have a stock sample from the age 25+ population, each respondent goes throughan individual-specific series of intervals. Hence, we have an unbalanced panel over the age rangestarting from 25 years old. Denote by ji0 the first age at which respondent i is observed and jiTi
the last age when he is observed. Hence we observe outcomes at ages ji = ji0, . . . , jiTi.
We first start with discrete outcomes which are absorbing states (e.g. disease diagnostic, mor-tality, benefit claiming). Record as hi,ji,m = 1 if the individual outcome m has occurred as of age ji.We assume the individual-specific component of the hazard can be decomposed in a time invariantand variant part. The time invariant part is composed of the effect of observed characteristics xithat are constant over the entire life course and initial conditions hi,j0,−m (outcomes other than theoutcome m) that are determined before the first age in which each individual is observed The time-varying part is the effect of previously diagnosed outcomes hi,ji−1,−m, on the hazard for m.1 Weassume an index of the form zm,ji = xiβm +hi,ji−1,−mγm +hi,j0,−mψm. Hence, the latent componentof the hazard is modeled as
h∗i,ji,m = xiβm + hi,ji−1,−mγm + hi,j0,−mψm + am,ji + εi,ji,m, (1)
m = 1, . . . ,M0, ji = ji0, . . . , ji,Ti, i = 1, . . . , N
The term εi,ji,m is a time-varying shock specific to age ji. We assume that this last shock is normallydistributed and uncorrelated across diseases. We approximate am,ji with an age spline with knotsat ages 35, 45, 55, 65, and 75. This simplification is made for computational reasons since thejoint estimation with unrestricted age fixed effects for each condition would imply a large numberof parameters. The absorbing outcome, conditional on being at risk, is defined as
hi,ji,m = maxI(h∗i,ji,m > 0), hi,ji−1,m
The occurrence of mortality censors observation of other outcomes in a current year.A number of restrictions are placed on the way feedback is allowed in the model. Table 6
documents restrictions placed on the transition model. We also include a set of other controls. Alist of such controls is given in Table 7 along with descriptive statistics.
We have five other types of outcomes:
1. First, we have binary outcomes which are not an absorbing state, such as starting smoking.We specify latent indices as in (1) for these outcomes as well but where the lag dependentoutcome also appears as a right-hand side variable. This allows for state-dependence.
2. Second, we have ordered outcomes. These outcomes are also modeled as in (1) recognizingthe observation rule is a function of unknown thresholds ςm. Similarly to binary outcomes,we allow for state-dependence by including the lagged outcome on the right-hand side.
3. The third type of outcomes we consider are censored outcomes, such as financial wealth. Forwealth, there are a non-negligible number of observations with zero and negative wealth. Forthese, we consider two part models where the latent variable is specified as in (1) but modelprobabilities only when censoring does not occur. In total, we have M outcomes.
4. The fourth type of outcomes are continuous outcomes modeled with ordinary least squares.For example, we model transitions in log(BMI). We allow for state-dependence by includingthe lagged outcome on the right-hand side.
1With some abuse of notation, ji − 1 denotes the previous age at which the respondent was observed.
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5. The final type of models are categorical, but without an ordering. For example, an individualcan transition to being out of the labor force, unemployed, or working (either full- or part-time). In situations like this, we utilize a multinomial logit model, including the laggedoutcome on the right-hand side.
The parameters θ1 =(βm, γm, ψm, ςmMm=1 ,
), can be estimated by maximum likelihood. Given
the normality distribution assumption on the time-varying unobservable, the joint probability of alltime-intervals until failure, right-censoring or death conditional on the initial conditions hi,j0,−m isthe product of normal univariate probabilities. Since these sequences, conditional on initial condi-tions, are also independent across diseases, the joint probability over all disease-specific sequencesis simply the product of those probabilities.
For a given respondent observed from initial age ji0 to a last age jTi, the probability of the
observed health history is (omitting the conditioning on covariates for notational simplicity)
l−0i (θ;hi,ji0) =
M−1∏m=1
jTi∏j=ji1
Pij,m(θ)(1−hij−1,m)(1−hij,M )
× jTi∏j=ji1
Pij,M(θ)
We use the −0 superscript to make explicit the conditioning on hi,ji0 = (hi,ji0,0, . . . , hi,ji0,M)′. Wehave limited information on outcomes prior to this age. The likelihood is a product of M terms withthe mth term containing only (βm, γm, ψm, ςm). This allows the estimation to be done seperatelyfor each outcome.
3.1.1 Further Details on Specific Transition Models
This section describes the modeling strategy for particular outcomes.
Employment Status Ultimately, we wish to simulate if an individual is out of the labor force,unemployed, working part-time, or working full-time at time t. We treat the estimation of thisas a two-stage process. In the first stage, we predict if the individual is out of the labor force,unemployed, or working for pay using a multinomial logit model. Then, conditional on working forpay, we estimate if the individual is working part- or full-time using a probit model.
Earnings We estimate last calendar year earnings models based on the current employment sta-tus, controlling for the prior employment status. Of particular concern are individuals with no earn-ings, representing approximately twenty-five percent of the unemployed and seventy-eight percentof those out of the labor force. This group is less than 0.5% of the full- and part-time populations.We use a two-stage process for those out of the labor force and unemployed. The first stage isa probit that estimates if the individual has any earnings. The second stage is an OLS model oflog(earnings) for those with non-zero earnings. For those working full- or part-time, we estimateOLS models of log(earnings).
Relationship Status We are interested in three relationship statuses: single, cohabitating, andmarried. In each case, we treat the transition from time t to time t + 1 as a two-stage process. Inthe first stage, we estimate if the individual will remain in their current status. In the second stage,we estimate which of the two other states the individual will transition to, conditional on leavingtheir current state.
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Childbearing We estimate the number of children born in two-years separately for women andmen. We model this using an ordered probit with three categories: no new births, one birth, andtwo births. Based on the PSID data, we found the exclusion of three or more births in a two-yearperiod to be appropriate.
3.1.2 Inverse Hyperbolic Sine Transformation
One problem fitting the wealth distribution is that it has a long right tail and some negative values.We use a generalization of the inverse hyperbolic sine transform (IHT) presented in MacKinnonand Magee (1990). First denote the variable of interest y. The hyperbolic sine transform is
y = sinh(x) =exp(x)− exp(−x)
2(2)
The inverse of the hyperbolic sine transform is
x = sinh−1(y) = h(y) = log(y + (1 + y2)1/2)
Consider the inverse transformation. We can generalize such transformation, first allowing for ashape parameter θ,
r(y) = h(θy)/θ (3)
Such that we can specify the regression model as
r(y) = xβ + ε, ε ∼ N(0, σ2) (4)
A further generalization is to introduce a location parameter ω such that the new transformationbecomes
g(y) =h(θ(y + ω))− h(θω)
θh′(θω)(5)
where h′(a) = (1 + a2)−1/2.We specify (4) in terms of the transformation g. The shape parameters can be estimated from
the concentrated likelihood for θ, ω. We can then retrieve β, σ by standard OLS.Upon estimation, we can simulate
g = xβ + ση
where η is a standard normal draw. Given this draw, we can retransform using (5) and (2)
h(θ(y + ω)) = θh′(θω)g + h(θω)
y =sinh [θh′(θω)g + h(θω)]− θω
θ
The included estimates table (estimates FAM.xml) gives parameter estimates for the transitionmodels.
4 Model for replenishing cohorts
We first discuss the empirical strategy, then present the model and estimation results. The modelfor replinishing cohorts integrates information coming from trends among younger cohorts with thejoint distribution of outcomes in the current population of age 25 respondents in the PSID.
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4.1 Model and estimation
Assume the latent model for y∗i = (y∗i1, . . . , y∗iM)′,
y∗i = µ+ εi,
where εi is normally distributed with mean zero and covariance matrix Ω. It will be useful to writethe model as
y∗i = µ+ LΩηi,
where LΩ is a lower triangular matrix such that LΩL′Ω = Ω and ηi = (ηi1, . . . , ηiM)′ are standardnormal. We observe yi = Γ(y∗i ) which is a non-invertible mapping for a subset of the M outcomes.For example, we have binary, ordered and censored outcomes for which integration is necessary.
The vector µ can depend on some variables which have a stable distribution over time zi (sayrace, gender and education). This way, estimation preserves the correlation with these outcomeswithout having to estimate their correlation with other outcomes. Hence, we can write
µi = ziβ
and the whole analysis is done conditional on zi.For binary and ordered outcomes, we fix Ωm,m = 1 which fixes the scale. Also we fix the location
of the ordered models by fixing thresholds as τ0 = −∞, τ1 = 0, τK = +∞, where K denotes thenumber of categories for a particular outcome. We also fix to zero the correlation between selectedoutcomes (say earnings) and their selection indicator. Hence, we consider two-part models for theseoutcomes. Because some parameters are naturally bounded, we also re-parameterize the problemto guarantee an interior solution. In particular, we parameterize
Ωm,m = exp(δm), m = m0 − 1, . . . ,M
Ωm,n = tanh(ξm,n)√
Ωm,mΩm,n, m, n = 1, . . . , N
τm,k = exp(γm,k) + τk−1, k = 2, . . . , Km − 1,m ordered
and estimate the (δm,m, ξm,n, γk) instead of the original parameters. The parameter values areestimated using the cmp package in Stata (Roodman, 2011). Table 8 gives parameter estimates forthe indices while Table 9 gives parameter estimates of the covariance matrix in the outcomes.
4.2 Trends for replenishing cohorts
Using the jointly estimated models previously described, we then assign outcomes to the replenishingcohorts, imposing trends for some health, risk factor, and social outcomes. We currently imposetrends on BMI, education, number of children, marital status, hypertension, and smoking statusfor these 25-26 year olds. These trends are estimated using the National Health Interview Survey(health and risk factors) or the American Community Survey (social outcomes). All trends arehalted after 2029. The trends are shown in Table 10, Table 11 and Table 12.
5 Government revenues and expenditures
This gives a limited overview of how revenues and expenditures of the government are computed.
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5.1 Medical costs estimation
In the FAM, a cost module links a person’s current state–demographics, economic status, currenthealth, risk factors, and functional status to 4 types of individual medical spending. The FAMmodels: total medical spending (medical spending from all payment sources), Medicare spending2,Medicaid spending (medical spending paid by Medicaid), and out of pocket spending (medicalspending by the respondent). These estimates are based on pooled weighted least squares regres-sions of each type of spending on risk factors, self-reported conditions, and functional status, withspending inflated to constant dollars using the medical component of the consumer price index. Weuse the 2007-2010 Medical Expenditure Panel Survey for these regressions for persons not Medicareeligible, and the 2007-2010 Medicare Current Beneficiary Survey for spending for those that areeligible for Medicare. Those eligible for Medicare include people eligible due to age (65+) or due todisability status. Comparisons of prevalences and question wording across these different sourcesare provided in Tables 3 and 4, respectively.
In the baseline scenario, this spending estimate can be interpreted as the resources consumedby the individual given the manner in which medicine is practiced in the United States during thepost-part D era (2006-2010). Models are estimated for total, Medicaid, out of pocket spending, andfor the Medicare spending.
Since Medicare spending has numerous components (Parts A and B are considered here), modelsare needed to predict enrollment. In 2004, 98.4% of all Medicare enrollees, and 99%+ of agedenrollees, were in Medicare Part A, and thus we assume that all persons eligible for Medicaretake Part A. We use the 2007-2010 MCBS to model take up of Medicare Part B for both newenrollees into Medicare, as well as current enrollees without Part B. Estimates are based on weightedprobit regression on various risk factors, demographic, and economic conditions. The PSID startingpopulation for the FAM does not contain information on Medicare enrollment. Therefore anothermodel of Part B enrollment for all persons eligible for Medicare is estimated via a probit, and usedin the first year of simulation to assign initial Part B enrollment status. Estimation results areshown in estimates table. The MCBS data over represents the portion enrolled in Part B, havinga 97% enrollment rate in 2004 instead of the 93.5% rate given by Medicare Trustee’s Report. Inaddition to this baseline enrollment probit, we apply an elasticity to premiums of -0.10, basedon the literature and simulation calibration for actual uptake through 2009 (Atherly et al., 2004;Buchmueller, 2006). The premiums are computed using average Part B costs from the previoustime step and the means-testing thresholds established by the ACA.
Since 2006, the Medicare Current Beneficiaries Survey (MCBS) contains data on Medicare PartD. The data gives the capitated Part D payment and enrollment. When compared to the summarydata presented in the CMS 2007 Trustee Report, the 2006 per capita cost is comparable betweenthe MCBS and the CMS. However, the enrollment is underestimated in the MCBS, 53% comparedto 64.6% according to CMS.
A cross-sectional probit model is estimated using years 2007-2010 to link demographics, economicstatus, current health, and functional status to Part D enrollment - see the estimates table. Toaccount for both the initial under reporting of Part D enrollment in the MCBS, as well as the CMSprediction that Part D enrollment will rise to 75% by 2012, the constant in the probit model isincreased by 0.22 in 2006, to 0.56 in 2012 and beyond. The per capita Part D cost in the MCBSmatches well with the cost reported from CMS. An OLS regression using demographic, currenthealth, and functional status is estimated for Part D costs based on capitated payment amounts.
2We estimate annual medical spending paid by specific parts of Medicare (Parts A, B, and D) and sum to get thetotal Medicare expenditures.
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The Part D enrollment and cost models are implemented in the Medical Cost module. The PartD enrollment model is executed conditional on the person being eligible for Medicare, and the costmodel is executed conditional on the enrollment model leading a true result, after the Monte Carlodecision. Otherwise the person has zero Part D cost. The estimated Part D costs are added withPart A and B costs to obtain total Medicare cost, and any medical cost growth assumptions arethen applied.
6 Implementation
The FAM is implemented in multiple parts. Estimation of the transition and cross sectional modelsis performed in Stata. The replenishing cohort model is estimated in Stata using the CMP package(Roodman, 2011). The simulation is implemented in C++ for speed and flexibility. Currently, thesimulation is run on Linux, Windows, and Mac OS X.
To match the two year structure of the PSID data used to estimate the transition models, theFAM simulation proceeds in two year increments. The end of each two year step is designed to occuron July 1st to allow for easier matching to population forecasts from Social Security. A simulationof the FAM proceeds by first loading a population representative of the age 25+ US populationin 2009, generated from PSID. In two year increments, the FAM applies the transition modelsfor mortality, health, working, wealth, earnings, and benefit claiming with Monte Carlo decisionsto calculate the new states of the population. The population is also adjusted by immigrationforecasts from the US Census Department, stratified by race and age. If incoming cohorts are beingused, the new 25/26 year olds are added to the population. The number of new 25/26 year oldsadded is consistent with estimates from the Census, stratified by race. Once the new states havebeen determined and new 25/26 year olds added, the cross sectional models for medical costs areperformed. Summary variables are then computed. Computation of medical costs includes thepersons that died to account for end of life costs. To reduce uncertainty due to the Monte Carlodecision rules, the simulation is performed multiple times (typically 100), and the mean of eachsummary variable is calculated across repetitions.
FAM simulation takes as inputs assumptions regarding the normal retirement age, real medicalcost growth, and interest rates. The default assumptions are taken from the 2010 Social SecurityIntermediate scenario, adjusted for no price increases after 2010. Therefore simulation results arein real 2009 dollars.
Different simulation scenarios are implemented by changing any of the following components:incoming cohort model, transition models, interventions that adjust the probabilities of specifictransition, and changes to assumptions on future economic conditions.
6.1 Intervention Module
The intervention module can adjust characteristics of individuals when they are first read intothe simulation “init interventions” or alter transitions within the simulation “interventions.” Atpresent, init interventions can act on chronic diseases, ADL/IADL status, program participation,and some demographic characteristics. Interventions within the simulation can currently act onmortality, chronic diseases, and some program participation variables.
Interventions can take several forms. The most commonly used is an adjustment to a transitionprobability. One can also delay the assignment of a chronic condition or cure an existing chroniccondition. Additional flexibility comes from selecting who is eligible for the intervention. Someexamples might help to make the interventions concrete.
13
• Example 1: Delay the enrollment into Social Security OASI by two years. In this scenarioclaiming of Social Security benefits is transitioned as normal. However, if a person is predictedto claim their benefits, then that status is not immediately assigned, but is instead assignedtwo years later.
• Example 2: Cure hypertension for those with no other chronic diseases. In this scenario anyindividual with hypertension (including those who have had hypertension for many years) iscured (hypertension status is set to 0), as long as they do not have other chronic diseases.This example uses the individuals chronic disease status as the eligibility criteria for theintervention.
• Example 3: Reduce the incidence of hypertension for half of men aged 55 to 65 by 10% in thefirst year of the simulation, gradually increasing the reduction to 20% after 10 years. Thisexample begins to show the flexibility in the intervention module. The eligibility criteria aremore complex (half of men in a specific age range are eligible) and the intervention changesover time. Mathematically, the intervention works by acting on the incidence probability, ρ.In the first year of the simulation, the probability is replaced by (1− 0.5 ∗ 0.1) ρ = 0.95ρ. Thebinary outcome is then assigned based on this new probability. Thus, at the population level,there is a 5% reduction in incidence for men aged 55 to 65, as desired. After 10 years, theprobability for this eligible population becomes (1− 0.5 ∗ 0.2) ρ = 0.9ρ.
More elaborate interventions can be programmed by the user.
7 Validation
We perform cross-validation and external corroboration exercises. Cross-validation is a test ofthe simulations internal validity that compares simulated outcomes to actual outcomes. Externalcorroboration compares model forecasts to others forecasts.
7.1 Cross-validation
The cross-validation exercise randomly samples half of the PSID respondent IDs for use in estimatingthe transition models. The respondents not used for estimation, but who were present in the PSIDsample in 1999, are then simulated from 1999 through 2013. Demographic, health, and economicoutcomes are compared between the simulated (FAM) and actual (PSID) populations.
Worth noting is how the composition of the population changes in this exercise. In 1999, thesample represents those 25 and older. Since we follow a fixed cohort, the age of the population willincrease to 39 and older in 2013. This has consequences for some measures in later years where theeligible population shrinks.
7.1.1 Demographics
Mortality and demographic measures are presented in Tables 13 and 14. Mortality incidence iscomparable between the simulated and observed populations. Demographic characteristics do notdiffer between the two.
14
7.1.2 Health Outcomes
Binary health outcomes are presented in Table 15. FAM underestimates the prevalence of ADL andIADL limitations compared to the crossvalidation sample. Binary outcomes, like cancer, diabetes,heart diesease, and stroke do not differ. FAM underpredicts hypertension and lung disease comparedto the crossvalidation sample.
7.1.3 Health Risk Factors
Risk factors are presented in Table 16. BMI is not statistically different between the two samples.Current smoking is not statistically different, but more individuals in the crossvalidation samplereport being former smokers.
7.1.4 Economic Outcomes
Binary economic outcomes are presented in Table 17. FAM underpredicts claiming of federal dis-ability and overpredicts Social Security retirement claiming. Supplemental Security claiming isnot statistically different between FAM and the crossvalidation sample. Working for pay is notstatistically different.
On the whole, the crossvalidation exercise is reassuring. There are differences that will beexplored and improved upon in the future.
7.2 External Corroboration
Finally, we compare FAM population forecasts to Census forecasts of the US population.. Here, wefocus on the full PSID population (25 and older) and those 65 and older. For this exercise, we beginthe simulation in 2009 and simulate the full population through 2049. Population projections arecompared to the 2012 Census projections for years 2012 through 2049. See resuts in Table 18. By2049, FAM forecasts for 25 and older remain within 2% of Census forecasts.
8 Baseline Forecasts
In this section we present baseline forecasts of the Future Americans Model. The figures show datafrom the PSID for the 25+ population from 1999 through 2009 and forecasts from the FAM for the25+ population beginning in 2009.
8.1 Disease Prevalence
Figure 2 depicts the six chronic conditions we project for men. And Figure 3 depicts the historicand forecasted values for women.
Figure 4 shows historic and forecasted levels for any ADL difficulties, three or more ADL dif-ficulties, any IADL difficulties, and two or more IADL difficulties for men 25 and older. Figure 5shows historic and forecasted levels for any ADL difficulties, three or more ADL difficulties, anyIADL difficulties, and two or more IADL difficulties for women 25 and older.
15
0.1
.2.3
.4.5
2000 2010 2020 2030 2040 2050
Cancer Ever
0.1
.2.3
.4.5
2000 2010 2020 2030 2040 2050
Diabetes Ever
0.1
.2.3
.4.5
2000 2010 2020 2030 2040 2050
Heart Disease Ever
0.1
.2.3
.4.5
2000 2010 2020 2030 2040 2050
Hypertension Ever
0.1
.2.3
.4.5
2000 2010 2020 2030 2040 2050
Lung Disease Ever
0.1
.2.3
.4.5
2000 2010 2020 2030 2040 2050
Stroke Ever
Figure 2: Historic and Forecasted Chronic Disease Prevalence for Men 25+
0.1
.2.3
.4
2000 2010 2020 2030 2040 2050
Cancer Ever
0.1
.2.3
.4
2000 2010 2020 2030 2040 2050
Diabetes Ever0
.1.2
.3.4
2000 2010 2020 2030 2040 2050
Heart Disease Ever
0.1
.2.3
.4
2000 2010 2020 2030 2040 2050
Hypertension Ever
0.1
.2.3
.4
2000 2010 2020 2030 2040 2050
Lung Disease Ever
0.1
.2.3
.4
2000 2010 2020 2030 2040 2050
Stroke Ever
Figure 3: Historic and Forecasted Chronic Disease Prevalence for Women 25+
16
.02
.04
.06
.08
.1
2000 2010 2020 2030 2040 2050
Any ADL difficulties
.02
.04
.06
.08
.1
2000 2010 2020 2030 2040 2050
3 or more ADL difficulties
.02
.04
.06
.08
.1
2000 2010 2020 2030 2040 2050
Any IADL difficulties
.02
.04
.06
.08
.12000 2010 2020 2030 2040 2050
2 or more IADL difficulties
Figure 4: Historic and Forecasted ADL and IADL Prevalence for Men 25+
0.0
5.1
.15
.2
2000 2010 2020 2030 2040 2050
Any ADL difficulties
0.0
5.1
.15
.2
2000 2010 2020 2030 2040 2050
3 or more ADL difficulties
0.0
5.1
.15
.2
2000 2010 2020 2030 2040 2050
Any IADL difficulties
0.0
5.1
.15
.2
2000 2010 2020 2030 2040 2050
2 or more IADL difficulties
Figure 5: Historic and Forecasted ADL and IADL Prevalence for Women 25+
9 Acknowledgments
The Future Elderly Model and Future Americans Model has been developed by a large team over thelast decade. Jay Bhattacharya, Eileen Crimmins, Christine Eibner, Etienne Gaudette, Geoff Joyce,
17
Darius Lakdawalla, Pierre-Carl Michaud, and Julie Zissimopoulos have all provided expert guidance.Adam Gailey, Baoping Shang, and Igor Vaynman provided programming and analytic support dur-ing the first years of FEM development at RAND. Jeff Sullivan then led the technical developmentfor several years. More recently, the University of Southern California research programming teamhas supported model development, including FAM development. These programmers include Patri-cia St. Clair, Laura Gascue, Henu Zhao, and Yuhui Zheng. Barbara Blaylock, Malgorzata Switek,and Wendy Cheng have greatly aided model development while working as research assistants atUSC.
10 Tables
Economic Outcomes Health Outcomes Other OutcomesWork Status BMI Category EducationEarnings Smoking Category PartneredWealth Hypertension Partner Type
Health Insurance
Table 1: Estimated outcomes in replenishing cohorts module
18
Eco
nom
icO
utc
om
es
Healt
hO
utc
om
es
Mari
tal
Sta
tus
Oth
er
Outc
om
es
Soci
alSec
uri
tyC
laim
ing
Mor
tality
Exit
Sin
gle
Insu
rance
Typ
eD
isab
ilit
yC
laim
ing
Hea
rtD
isea
seE
xit
Coh
abit
atio
nN
on-Z
ero
Cap
ital
Inco
me
Can
cer
Exit
Mar
ried
Cap
ital
Inco
me
(if
non
-zer
o)H
yp
erte
nsi
onSin
gle
toM
arri
edN
on-z
ero
Gov
ernm
ent
Tra
nsf
ers
Dia
bet
esC
ohab
itat
ion
toM
arri
edG
over
nm
ent
Tra
nsf
ers
(if
non
-zer
o)L
ung
Dis
ease
Mar
ried
toC
ohab
itat
ion
Non
-zer
oW
ealt
hSta
rtSm
okin
gW
ealt
h(i
fnon
-zer
o)Sto
pSm
okin
gL
abor
For
ceSta
tus
(out,
unem
plo
yed,
wor
kin
g)A
DL
Sta
tus
Em
plo
yed
Full-
orP
art-
tim
e(i
fw
orkin
g)IA
DL
Sta
tus
Any
Ear
nin
gs(i
fU
nem
plo
yed)
Bir
ths/
Pat
ernit
yA
ny
Ear
nin
gs(i
fN
otin
Lab
orF
orce
)Sel
f-re
por
ted
Hea
lth
Ear
nin
gs(i
fF
ull-t
ime)
BM
IE
arnin
gs(i
fP
art-
tim
e)P
artn
erD
eath
Ear
nin
gs(i
fU
nem
plo
yed
and
any)
Ear
nin
gs(i
fN
otin
Lab
orF
orce
and
any)
Tab
le2:
Est
imat
edou
tcom
esin
tran
siti
ons
module
19
Pre
vale
nce
%Sou
rce
(yea
rs,
ages
)C
ance
rH
eart
Dis
ease
sStr
oke
Dia
bet
esH
yp
erte
nsi
onL
ung
Dis
ease
Ove
rwei
ght
Ob
ese
HR
S(2
004-
2008
,50
-64)
8%14
%4%
16%
45%
7%37
%36
%H
RS
(200
4-20
08,
65+
)19
%31
%11
%22
%64
%12
%38
%26
%M
CB
S(2
007-
2010
,65
+)
19%
41%
11%
25%
68%
17%
38%
26%
ME
PS
(200
7-20
10,
25-4
9)2%
6%1%
4%18
%4%
35%
30%
ME
PS
(200
7-20
10,
50-6
4)6%
16%
4%14
%46
%7%
37%
34%
ME
PS
(200
7-20
10,
65+
)14
%36
%12
%21
%68
%11
%38
%27
%N
HIS
(200
7-20
09,
25-4
9)2%
6%1%
4%16
%4%
34%
31%
NH
IS(2
007-
2009
,50
-64)
7%14
%3%
13%
41%
7%36
%35
%N
HIS
(200
7-20
09,
65+
)17
%32
%9%
19%
61%
10%
36%
27%
PSID
(200
7-20
11,
25-4
9)2%
5%1%
4%13
%3%
34%
28%
PSID
(200
7-20
11,
50-6
4)7%
15%
3%13
%36
%8%
39%
28%
PSID
(200
7-20
11,
65+
)16
%35
%10
%20
%55
%13
%39
%21
%
Tab
le3:
Hea
lth
condit
ion
pre
vale
nce
sin
surv
eydat
a
20
Surv
eyD
isea
seP
SID
/HR
SN
HIS
ME
PS
MC
BS
Can
cer
Has
adoct
orev
erto
ldyo
uth
atyo
uhav
eca
nce
ror
am
alig
nan
ttu
mor
,ex
cludin
gm
inor
skin
cance
rs?
Hav
eyo
uev
erb
een
told
be
adoct
oror
other
hea
lth
pro
fess
ional
that
you
had
cance
ror
am
alig
-nan
acy
ofan
ykin
d?
(WH
EN
RE
-C
OD
ED
,SK
INC
AN
CE
RS
WE
RE
EX
CL
UD
ED
)
Lis
tal
lth
eco
ndit
ions
that
hav
eb
other
ed(t
he
per
son)
from
(ST
AR
Tti
me)
to(E
ND
tim
e)C
CS
codes
for
the
condit
ions
list
are
11-2
1,24
-45
Has
adoct
orev
erto
ldyo
uth
atyo
uhad
any
(oth
er)
kin
dof
cance
rm
a-lign
ancy
,or
tum
orot
her
than
skin
cance
r?
Hea
rtD
isea
ses
Has
adoct
orev
erto
ldyo
uth
atyo
uhad
ahea
rtat
tack
,co
ronar
yhea
rtdis
ease
,an
gina,
conge
stiv
ehea
rtfa
ilure
,or
other
hea
rtpro
ble
ms?
Fou
rse
par
ate
ques
tion
sw
ere
aske
dab
out
whet
her
ever
told
by
ado-
coto
ror
oith
erhea
lth
pro
fess
ional
that
had
:C
HD
,A
ngi
na,
MI,
other
hea
rtpro
ble
ms.
Hav
eyo
uev
erb
een
told
by
adoc-
tor
orhea
lth
pro
fess
ional
that
you
hav
eC
HD
;A
ngi
na;
MI;
other
hea
rtpro
ble
ms
Six
separ
ate
ques
tion
sw
ere
aske
dab
out
whet
her
ever
told
by
adoc-
tor
that
had
:A
ngi
na
orM
I;C
HD
;ot
her
hea
rtpro
ble
ms
(incl
uded
four
ques
tion
s)Str
oke
Has
adoct
orev
erto
ldyo
uth
atyo
uhad
ast
roke
?H
ave
you
EV
ER
bee
nto
ldby
adoc-
tor
orot
her
hea
lth
pro
fess
ional
that
you
had
ast
roke
?
IfF
emal
e,ad
d:
[Oth
erth
andur-
ing
pre
gnan
cy,]
Hav
eyo
uev
erb
een
told
by
adoct
oror
hea
lth
pro
fes-
sion
alth
atyo
uhav
ea
stro
keor
TIA
(tra
nsi
ent
isch
emic
atta
ck)
[Sin
ce(P
RE
V<
SU
PP
.R
D.
INT
.D
AT
E),
]has
adoct
or(e
ver)
told
(you
/SP
)th
at(y
ou/h
e/sh
e)had
ast
roke
,a
bra
inhem
orrh
age,
ora
cere
bro
vasc
ula
rac
ciden
t?D
iab
etes
Has
adoct
orev
erto
ldyo
uth
atyo
uhav
edia
bet
esor
hig
hblo
od
suga
r?If
Fem
ale,
add:
[Oth
erth
anduri
ng
pre
gnan
cy,]
Hav
eyo
uev
erb
een
told
by
adoct
oror
hea
lth
pro
fess
ional
that
you
hav
edia
bet
esor
suga
rdi-
abet
es?
IfF
emal
e,ad
d:
[Oth
erth
anduri
ng
pre
gnan
cy,]
Hav
eyo
uhev
erb
een
told
by
adoct
oror
hea
lth
pro
fes-
sion
alth
atyo
uhav
edia
bet
esor
suga
rdia
bet
es?
Has
adoct
or(e
ver)
told
(you
/SP
)th
at(y
ou/h
e/sh
e)had
dia
bet
es,
hig
hblo
od
suga
r,or
suga
rin
(you
r/his
/her
)uri
ne?
[DO
NO
TIN
CL
UD
EB
OE
RD
ER
-L
INE
PR
EG
NA
NC
Y,
OR
PR
E-
DIA
BE
TE
ICD
IAB
ET
ES.]
Hyp
erte
nsi
onH
asa
doct
orve
rto
ldyo
uth
atyo
uhav
ehig
hblo
od
pre
ssure
orhyp
er-
tensi
on?
Hav
eyo
uE
VE
Rb
een
told
by
adoc-
tor
orot
her
hea
lth
pro
fess
ional
that
you
had
Hyp
erte
nsi
on,
also
called
hig
hblo
od
pre
ssure
?
Hav
eyo
uE
VE
Rb
een
told
by
adoc-
tor
orot
her
hea
lth
pro
fess
ional
that
you
had
Hyp
erte
nsi
on,
also
called
hig
hblo
od
pre
ssure
?
Has
adoct
or(e
ver)
told
(you
/SP
)th
at(y
ou/h
e/sh
e)(s
till)
(had
)(h
ave/
has
)hyp
erte
nsi
on,
som
e-ti
mes
called
hig
hblo
od
pre
ssure
?L
ung
Dis
ease
Has
adoct
orev
erto
ldyo
uth
atyo
uhav
ech
ronic
lung
dis
ease
such
asc
hro
nic
bro
nch
itis
orem
phy-
sem
a?[I
WE
R:
DO
NO
TIN
-C
LU
DE
AST
HM
A]
Ques
tion
1:D
uri
ng
the
PA
ST
12M
ON
TH
S,
hav
eyo
uev
erb
een
told
by
adoct
oror
other
hea
lth
pro
fes-
sion
alth
atyo
uhad
chro
nic
bro
nch
i-ti
s?Q
ues
tion
2:H
ave
you
EV
ER
bee
nto
ldby
adoco
tor
orot
her
hea
lth
pro
fess
ional
that
you
had
emphyse
ma?
Lis
tal
lth
eco
ndit
ions
that
hav
eb
other
ed(t
he
per
son)
from
(ST
AR
Tti
me)
to(E
ND
tim
e)C
CS
codes
for
the
condit
ions
list
are
127,
129-
312
Has
adoct
or(e
ver)
told
(you
/SP
)th
at(y
ou/h
e/sh
e)had
em-
physe
ma,
asth
ma,
orC
OP
D?
[CO
PD
=C
HR
ON
ICO
BST
RU
C-
TIV
EP
UL
MO
NA
RY
DIS
EA
SE
.]
Ove
rwei
ght
Sel
f-re
por
ted
body
wei
ght
and
hei
ght
Ob
ese
Tab
le4:
Surv
eyques
tion
suse
dto
det
erm
ine
hea
lth
condit
ions
21
Typ
eA
tri
skM
ean
/fra
ctio
n
Dis
ease
hea
rtd
isea
seb
ien
nia
lin
cid
ence
un
dia
gnos
ed0.
02hyp
erte
nsi
onb
ien
nia
lin
cid
ence
un
dia
gnos
ed0.
04st
roke
bie
nn
ial
inci
den
ceu
nd
iagn
osed
0.01
lun
gd
isea
seb
ienn
ial
inci
den
ceu
nd
iagn
osed
0.01
can
cer
bie
nn
ial
inci
den
ceu
nd
iagn
osed
0.01
dia
bet
esb
ien
nia
lin
cid
ence
un
dia
gnos
ed0.
02
Ris
kF
acto
rs
Sm
okin
gS
tatu
sn
ever
smok
edor
der
edal
l0.
50ex
smok
eror
der
edal
l0.
29cu
rren
tsm
oker
ord
ered
all
0.20
Log
BM
Ico
nti
nu
ous
all
3.30
AD
LS
tatu
s
no
AD
Ls
ord
ered
all
0.90
1A
DL
ord
ered
all
0.04
2A
DL
Sor
der
edal
l0.
023+
AD
LS
order
edal
l0.
03
IAD
LS
tatu
sn
oIA
DL
sor
der
edal
l0.
891
IAD
Lor
der
edal
l0.
072+
IAD
Ls
ord
ered
all
0.04
LF
P&
Ben
efits
Em
plo
ym
ent
Sta
tus
out
ofla
bor
forc
ep
reva
len
ceal
l0.
26u
nem
plo
yed
pre
vale
nce
all
0.06
par
tti
me
pre
vale
nce
all
0.18
full
tim
ep
reva
len
ceal
l0.
51S
Sb
enefi
tre
ceip
tb
ien
nia
lin
cid
ence
elig
ible
&n
otre
ceiv
ing
0.07
DI
ben
efit
rece
ipt
pre
vale
nce
elig
ible
&ag
e<
650.
03A
ny
hea
lth
insu
ran
cep
reva
len
ceag
e<
650.
83S
SI
rece
ipt
pre
vale
nce
all
0.02
Fam
ily
Mar
ital
stat
us
sin
gle
pre
vale
nce
all
0.28
coh
abit
atin
gp
reva
len
ceal
l0.
09m
arri
edp
reva
len
ceal
l0.
64
Ch
ild
bea
rin
gn
och
ild
ren
bie
nn
ial
inci
den
cefe
mal
e0.
911
chil
db
ien
nia
lin
cid
ence
fem
ale
0.09
2ch
ild
ren
bie
nn
ial
inci
den
cefe
mal
e0.
00F
inan
cial
fin
anci
alw
ealt
hm
edia
nal
ln
on-z
ero
wea
lth
60.2
8R
esou
rces
earn
ings
med
ian
wor
kin
gfu
llti
me
18.1
7ea
rnin
gsm
edia
nw
orkin
gp
art
tim
e40
.06
($K
2009
)w
ealt
hn
on-z
ero
pre
vale
nce
all
0.95
Tab
le5:
Outc
omes
inth
etr
ansi
tion
model
.E
stim
atio
nsa
mple
isP
SID
1999
-201
3w
aves
.
22
Val
ue
atti
meT−
1O
utc
ome
atti
meT
Hea
rtL
ung
Sm
okin
gN
urs
ing
Non
zero
dis
ease
hyp
erte
nsi
onst
roke
dis
ease
dia
bet
esca
nce
rdis
abilit
ym
orta
lity
stat
us
BM
IA
ny
HI
DI
Cla
imSS
Cla
imD
BC
laim
SSI
Cla
imH
ome
Wor
kE
arnin
gsW
ealt
hW
ealt
hH
eart
dis
ease
XX
XX
XX
XX
XX
XX
XX
XB
lood
pre
ssure
XX
XX
XX
XX
XX
XX
XX
XX
Str
oke
XX
XX
XX
XX
XX
XX
XX
Lung
dis
ease
XX
XX
XX
XX
XX
XX
XX
Dia
bet
esX
XX
XX
XX
XX
XX
XX
XX
XX
Can
cer
XX
XX
XX
XX
XX
XX
XX
XD
isab
ilit
yX
XX
XX
XX
XX
XX
XX
XC
laim
edD
IX
XX
XX
XX
XX
Cla
imed
SS
XX
XX
XX
XC
laim
edD
BX
XX
XX
XC
laim
edSSI
XW
ork
XX
XX
XX
XX
Ear
nin
gsX
XX
XX
XX
XX
Non
zero
wea
lth
XX
XX
XX
XX
XX
Wea
lth
XX
XX
XX
XX
XX
Nurs
ing
hom
est
ayX
XX
X
Tab
le6:
Res
tric
tion
son
tran
siti
onm
odel
.X
indic
ates
that
anou
tcom
eat
tim
eT−
1is
allo
wed
inth
etr
ansi
tion
model
for
anou
tcom
eat
tim
eT
.
23
StandardControl variable Mean deviation Minimum MaximumNon-hispanic black 0.112 0.315 0 1Hispanic 0.127 0.333 0 1Single 0.343 0.475 0 1Cohabitating 0.0540 0.226 0 1Married 0.603 0.489 0 1Less than high school 0.134 0.340 0 1High school/GED/some college/AA 0.552 0.497 0 1College graduate 0.209 0.407 0 1More than college 0.105 0.307 0 1Doctor ever - heart disease 0.141 0.348 0 1Doctor ever - hypertension 0.266 0.442 0 1Doctor ever - stroke 0.0319 0.176 0 1Doctor ever - chronic lung disease 0.0675 0.251 0 1Doctor ever - cancer 0.0555 0.229 0 1Doctor ever - diabetes 0.0925 0.290 0 1Never smoked 0.473 0.499 0 1Former smoker 0.347 0.476 0 1Current smoker 0.180 0.384 0 1No ADL limitations 0.868 0.338 0 11 ADL limitation 0.0595 0.237 0 12 ADL limitations 0.0263 0.160 0 13 or more ADL limitations 0.0458 0.209 0 1No IADL limitations 0.866 0.341 0 11 IADL limitation 0.0859 0.280 0 12 or more IADL limitations 0.0481 0.214 0 125 < BMI < 30 0.364 0.481 0 130 < BMI < 35 0.165 0.371 0 135 < BMI < 40 0.0665 0.249 0 1BMI > 40 0.0376 0.190 0 1Any Social Security income LCY 0.200 0.400 0 1Any Disability income LCY 0.0387 0.193 0 1Any Supplemental Security Income LCY 0.0188 0.136 0 1Any health insurance LCY 0.876 0.329 0 1Out of labor force 0.318 0.466 0 1Unemployed 0.0619 0.241 0 1Working part-time 0.177 0.381 0 1Working full-time 0.443 0.497 0 1Earnings in 1000s capped at 200K 34.02 40.04 0 200Wealth in 1000s capped at 2 million 270.1 457.2 -1974 2000
Table 7: Desciptive statistics for variables in 2009 PSID ages 25+ sample used as simulation stockpopulation
24
Num
ber
ofE
duca
tion
Par
tner
ship
Wei
ght
Sm
okin
gIn
lab
orbio
logi
cal
Cov
aria
tele
vel
Par
tner
edty
pe
stat
us
stat
us
Hyp
erte
nsi
onfo
rce
childre
nN
on-h
ispan
icbla
ck-0
.30
-0.7
6-0
.59
0.37
-0.4
00.
290.
190.
46H
ispan
ic-0
.11
-0.0
3-0
.08
0.19
-0.6
1-0
.22
0.02
0.26
Mal
e-0
.28
0.10
-0.2
00.
140.
210.
100.
59-0
.26
Les
sth
anH
S/G
ED
0.00
-0.0
30.
910.
170.
850.
10-0
.82
-0.3
4C
olle
ge0.
00-0
.18
-0.7
9-0
.46
-0.6
9-0
.17
0.74
-0.0
5B
eyon
dco
lleg
e0.
00-0
.29
-1.5
3-0
.86
-1.0
8-0
.49
0.96
0.28
R’s
mot
her
less
than
hig
hsc
hool
-0.2
7-0
.02
-0.1
10.
000.
000.
00-0
.03
0.19
R;s
mot
her
som
eco
lleg
e0.
29-0
.10
0.27
0.00
0.00
0.00
-0.1
3-0
.14
R’s
mot
her
colleg
egr
aduat
e0.
57-0
.19
0.32
0.00
0.00
0.00
-0.1
0-0
.35
R’s
fath
erle
ssth
anhig
hsc
hool
-0.2
60.
05-0
.09
0.00
0.00
0.00
0.08
0.11
R;s
fath
erso
me
colleg
e0.
31-0
.18
0.24
0.00
0.00
0.00
-0.1
0-0
.33
R’s
fath
erco
lleg
egr
aduat
e0.
69-0
.11
0.38
0.00
0.00
0.00
-0.3
0-0
.47
Poor
asa
child
-0.2
00.
01-0
.09
0.00
0.00
0.00
-0.0
20.
16W
ealt
hy
asa
child
-0.0
7-0
.04
-0.0
90.
000.
000.
00-0
.04
0.12
Fai
ror
poor
hea
lth
bef
ore
age
17-0
.20
-0.2
3-0
.08
0.00
0.00
0.00
-0.1
6-0
.03
Age
25or
26-0
.13
-0.1
9-0
.27
-0.1
1-0
.03
-0.1
2-0
.04
-0.2
6C
onst
ant
1.49
0.95
0.84
0.17
0.16
-1.7
70.
880.
40
Tab
le8:
Par
amet
eres
tim
ates
for
late
nt
model
:co
ndit
ional
mea
ns
and
thre
shol
ds.
Sam
ple
isre
spon
den
tsag
e25
-30
in20
05-2
011
PSID
wav
es
25
Num
ber
ofE
duca
tion
Par
tner
ship
Wei
ght
Sm
okin
gIn
lab
orbio
logi
cal
leve
lP
artn
ered
typ
est
atus
stat
us
Hyp
erte
nsi
onfo
rce
childre
nE
duca
tion
leve
l1.
000
Par
tner
ed0.
109
1.00
0P
artn
ersh
ipty
pe
0.68
50.
000
1.00
0W
eigh
tst
atus
0.17
10.
022
0.14
91.
000
Sm
okin
gst
atus
0.04
1-0
.116
-0.1
42-0
.030
1.00
0H
yp
erte
nsi
on0.
103
-0.1
020.
113
0.36
80.
013
1.00
0In
lab
orfo
rce
-0.3
04-0
.107
-0.1
88-0
.053
-0.0
22-0
.057
1.00
0N
um
ber
ofbio
logi
cal
childre
n-0
.455
0.25
0-0
.062
-0.0
19-0
.040
-0.0
08-0
.034
1.00
0
Tab
le9:
Par
amet
eres
tim
ates
for
late
nt
model
:par
amet
eriz
edco
vari
ance
mat
rix.
Sam
ple
isre
spon
den
tsag
e25
-30
in20
05-2
011
PSID
wav
es
26
Yea
rH
yp
erte
nsi
onO
verw
eigh
tO
bes
e1
Ob
ese
2O
bes
e3
Nev
erSm
oked
For
mer
Sm
oker
Curr
ent
Sm
oker
2009
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
2010
1.00
1.00
1.03
1.00
1.01
1.00
1.00
0.99
2011
0.99
1.00
1.05
1.01
1.03
1.01
0.99
0.98
2012
0.99
1.01
1.07
1.01
1.04
1.01
0.99
0.98
2013
0.99
1.01
1.09
1.02
1.06
1.01
0.99
0.97
2014
0.99
1.01
1.11
1.02
1.07
1.02
0.98
0.96
2015
0.99
1.02
1.13
1.03
1.08
1.02
0.98
0.95
2016
0.98
1.04
1.15
1.03
1.10
1.03
0.98
0.94
2017
0.95
1.13
1.17
1.04
1.11
1.03
0.97
0.94
2018
0.96
1.13
1.18
1.05
1.13
1.03
0.97
0.93
2019
0.97
1.13
1.21
1.06
1.14
1.04
0.97
0.92
2020
0.97
1.12
1.23
1.08
1.16
1.04
0.96
0.91
2021
0.97
1.11
1.26
1.09
1.17
1.04
0.96
0.91
2022
0.97
1.11
1.28
1.11
1.19
1.05
0.95
0.90
2023
0.97
1.10
1.29
1.13
1.20
1.05
0.95
0.89
2024
0.97
1.09
1.31
1.15
1.22
1.05
0.95
0.88
2025
0.97
1.08
1.32
1.18
1.24
1.06
0.94
0.87
2026
0.97
1.07
1.32
1.21
1.25
1.06
0.94
0.87
2027
0.97
1.04
1.37
1.24
1.27
1.06
0.94
0.86
2028
0.98
1.01
1.42
1.25
1.28
1.07
0.93
0.85
2029
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
2030
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
2031
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
2032
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
2033
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
2034
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
2035
1.00
1.00
1.44
1.26
1.30
1.07
0.93
0.84
Tab
le10
:H
ealt
han
dri
skfa
ctor
tren
ds
for
reple
nis
hin
gco
hor
ts,
pre
vale
nce
sre
lati
veto
2009
27
Yea
rL
ess
than
HS
HS
Gra
dC
olle
geG
rad
Gra
duat
eSch
ool
2009
1.00
1.00
1.00
1.00
2010
0.98
0.99
1.02
1.04
2011
0.96
0.98
1.03
1.08
2012
0.93
0.97
1.05
1.12
2013
0.91
0.96
1.06
1.17
2014
0.89
0.95
1.08
1.21
2015
0.87
0.94
1.09
1.26
2016
0.85
0.93
1.11
1.31
2017
0.83
0.92
1.12
1.36
2018
0.81
0.91
1.14
1.41
2019
0.79
0.90
1.15
1.46
2020
0.77
0.88
1.16
1.51
2021
0.75
0.87
1.18
1.57
2022
0.73
0.86
1.19
1.63
2023
0.71
0.85
1.20
1.68
2024
0.69
0.84
1.21
1.74
2025
0.67
0.83
1.23
1.80
2026
0.66
0.81
1.24
1.87
2027
0.64
0.80
1.25
1.93
2028
0.62
0.79
1.26
1.99
2029
0.60
0.78
1.27
2.06
2030
0.60
0.78
1.27
2.06
2031
0.60
0.78
1.27
2.06
2032
0.60
0.78
1.27
2.06
2033
0.60
0.78
1.27
2.06
2034
0.60
0.78
1.27
2.06
2035
0.60
0.78
1.27
2.06
Tab
le11
:E
duca
tion
tren
ds
for
reple
nis
hin
gco
hor
ts,
pre
vale
nce
sre
lati
veto
2009
28
Yea
rN
oC
hildre
nO
ne
Child
Tw
oC
hildre
nT
hre
eC
hid
ren
Fou
ror
Mor
eC
hildre
nP
artn
ered
Mar
ried
2009
1.00
1.00
1.00
1.00
1.00
1.00
1.00
2010
1.01
1.00
0.99
0.98
0.98
1.00
0.98
2011
1.01
0.99
0.98
0.97
0.95
0.99
0.96
2012
1.02
0.99
0.97
0.95
0.93
0.99
0.94
2013
1.03
0.98
0.96
0.93
0.90
0.99
0.91
2014
1.03
0.98
0.95
0.91
0.88
0.99
0.89
2015
1.04
0.97
0.94
0.90
0.86
0.98
0.87
2016
1.05
0.97
0.92
0.88
0.84
0.98
0.85
2017
1.05
0.96
0.91
0.87
0.82
0.98
0.82
2018
1.06
0.95
0.90
0.85
0.79
0.98
0.80
2019
1.07
0.95
0.89
0.83
0.77
0.98
0.78
2020
1.07
0.94
0.88
0.82
0.75
0.98
0.76
2021
1.08
0.94
0.87
0.80
0.73
0.98
0.73
2022
1.09
0.93
0.86
0.79
0.72
0.97
0.71
2023
1.09
0.93
0.85
0.77
0.70
0.97
0.69
2024
1.10
0.92
0.84
0.76
0.68
0.97
0.66
2025
1.11
0.92
0.83
0.75
0.66
0.97
0.64
2026
1.11
0.91
0.82
0.73
0.64
0.98
0.62
2027
1.12
0.90
0.81
0.72
0.63
0.98
0.60
2028
1.13
0.90
0.80
0.70
0.61
0.98
0.57
2029
1.13
0.89
0.79
0.69
0.59
0.98
0.55
2030
1.13
0.89
0.79
0.69
0.59
0.98
0.55
2031
1.13
0.89
0.79
0.69
0.59
0.98
0.55
2032
1.13
0.89
0.79
0.69
0.59
0.98
0.55
2033
1.13
0.89
0.79
0.69
0.59
0.98
0.55
2034
1.13
0.89
0.79
0.69
0.59
0.98
0.55
2035
1.13
0.89
0.79
0.69
0.59
0.98
0.55
Tab
le12
:Soci
altr
ends
for
reple
nis
hin
gco
hor
ts,
pre
vale
nce
sre
lati
veto
2009
29
2001 2007 2013FAM PSID FAM PSID FAM PSID
Outcome mean mean p mean mean p mean mean pDied 0.014 0.018 0.013 0.019 0.023 0.133 0.027 0.025 0.514
Table 13: Crossvalidation of 1999 cohort: Mortality in 2001, 2007, and 2013
2001 2007 2013FAM PSID FAM PSID FAM PSID
Outcome mean mean p mean mean p mean mean pAge on July 1st 49.120 49.022 0.668 53.079 53.379 0.197 56.759 57.959 0.000Black 0.094 0.093 0.742 0.093 0.088 0.228 0.094 0.092 0.710Hispanic 0.075 0.077 0.604 0.080 0.084 0.342 0.084 0.093 0.058Male 0.457 0.460 0.643 0.455 0.463 0.296 0.451 0.458 0.443
Table 14: Crossvalidation of 1999 cohort: Demographic outcomes in 2001, 2007, and 2013
2001 2007 2013FAM PSID FAM PSID FAM PSID
Outcome mean mean p mean mean p mean mean pAny ADLs 0.079 0.064 0.000 0.102 0.126 0.000 0.124 0.142 0.004Any IADLs 0.098 0.113 0.001 0.111 0.130 0.000 0.129 0.170 0.000Cancer 0.041 0.036 0.034 0.071 0.059 0.002 0.101 0.103 0.667Diabetes 0.066 0.062 0.233 0.100 0.092 0.090 0.136 0.145 0.108Heart Disease 0.098 0.106 0.095 0.135 0.152 0.002 0.175 0.173 0.792Hypertension 0.185 0.174 0.067 0.287 0.272 0.030 0.385 0.410 0.004Lung Disease 0.038 0.039 0.606 0.062 0.058 0.190 0.084 0.091 0.174Stroke 0.019 0.021 0.412 0.027 0.034 0.015 0.037 0.049 0.001
Table 15: Crossvalidation of 1999 cohort: Binary health outcomes in 2001, 2007, and 2013
30
2001 2007 2013FAM PSID FAM PSID FAM PSID
Outcome mean mean p mean mean p mean mean pBMI 26.690 26.723 0.671 27.379 27.397 0.850 27.848 27.639 0.039Current smoker 0.197 0.200 0.521 0.162 0.167 0.461 0.136 0.146 0.108Ever smoked 0.481 0.513 0.000 0.479 0.525 0.000 0.472 0.531 0.000
Table 16: Crossvalidation of 1999 cohort: Risk factor outcomes in 2001, 2007, and 2013
2001 2007 2013FAM PSID FAM PSID FAM PSID
Outcome mean mean p mean mean p mean mean pClaiming SSDI 0.017 0.023 0.005 0.019 0.033 0.000 0.022 0.049 0.000Claiming OASI 0.215 0.192 0.000 0.247 0.218 0.000 0.316 0.284 0.000Claiming SSI 0.017 0.016 0.434 0.015 0.016 0.435 0.015 0.017 0.528Working for pay 0.658 0.683 0.000 0.630 0.657 0.000 0.601 0.598 0.789
Table 17: Crossvalidation of 1999 cohort: Binary economic outcomes in 2001, 2007, and 2013
31
Yea
rC
ensu
s25
+FA
MM
inim
al25
+C
ensu
s65
+FA
MM
inim
al65
+20
0920
2.1
202.
039
.639
.420
1120
6.6
206.
041
.440
.520
1321
1.0
209.
644
.743
.120
1521
5.9
214.
047
.746
.220
1722
0.9
218.
350
.848
.920
1922
5.5
222.
354
.251
.120
2122
9.8
225.
957
.754
.020
2323
3.9
229.
161
.456
.320
2523
8.0
232.
665
.159
.420
2724
1.9
236.
268
.462
.620
2924
5.7
239.
571
.465
.620
3124
9.3
242.
873
.868
.020
3325
2.9
245.
575
.568
.720
3525
6.0
247.
877
.370
.320
3725
9.2
250.
078
.870
.120
3926
2.6
252.
479
.470
.220
4126
5.8
255.
179
.969
.620
4326
9.0
258.
080
.470
.720
4527
2.2
260.
781
.371
.320
4727
5.3
263.
182
.271
.620
4927
8.4
265.
683
.271
.9
Tab
le18
:P
opula
tion
fore
cast
s:C
ensu
sco
mpar
edto
FA
M
32
References
Atherly, A., Dowd, B. E., and Feldman, R. (2004). The effect of benefits, premiums, and healthrisk on health plan choice in the medicare program. Health services research, 39(4p1):847–864.
Buchmueller, T. (2006). Price and the health plan choices of retirees. Journal of Health Economics,25(1):81–101.
Goldman, D. P., Shekelle, P. G., Bhattacharya, J., Hurd, M., and Joyce, G. F. (2004). Health statusand medical treatment of the future elderly. Technical report, DTIC Document.
MacKinnon, J. G. and Magee, L. (1990). Transforming the dependent variable in regression models.International Economic Review, pages 315–339.
Roodman, D. (2011). Fitting fully observed recursive mixed-process models with cmp. StataJournal, 11(2):159–206(48).
Smith, K. and Favreault, M. (2013). A primer on modeling income in the near term, version 7.Technical report, The Urban Institute.
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