Mother’s, Household, and Community U.S. Migration Experience and Infant Mortality in

MexicoErin R. Hamilton, Andres Villarreal, and Robert A. Hummer

Department of Sociology and Population Research Center, The University of Texas at Austin This research was supported by NICHD Grants 1R01-HD-043371, 5 R24 HD042849, and 5 T23 HD041019.Distribution of Origins of Recent U.S.-bound

Migrants in Mexico: Municipal Migration Prevalence, 2000

Research QuestionsDo individual, household, and community U.S. migration experience associate with individual-level infant mortality outcomes in Mexico?

How does the infant mortality rate (IMR) of non-migrant and U.S.-returned migrant women in Mexico compare to the IMR of women of Mexican origin in the U.S.?

Why would we expect U.S. migration experience to associate with infant mortality in Mexico?•Individual level: mother’s own experience– Resources accessed through migration may be invested in maternal and

child health (e.g. Donato, Kanaiaupuni, & Stainback, 2003) – Healthy migrant selectivity (Palloni & Morenoff, 2001; Hummer et al.,

1999; see also Landale, Oropesa, & Gorman, 2000) •Household level– Migration is a household-level decision, benefiting non-migrating

members (Stark & Bloom, 1985); thus, resources and information remitted back home may benefit mothers and infants, especially if accessed directly by mothers (Grasmuck & Pessar, 1991; Frank & Hummer, 2002; Frank, 2005)

– However, the absence and departure of household members may be disruptive (Kanaiaupuni & Donato, 1999; Frank, 2005)

•Community-level– Money remitted back to Mexico leads to economic development (Durand

et al., 1996) – After migration becomes institutionalized in a community, its

developmental benefits are felt by non-migrating community members (Kanaiaupuni & Donato, 1999)

•Rural versus Urban Differences– We may expect the relationship between infant mortality and migration to

differ between rural and urban places because migration, health, and development patterns differ between rural and urban places

How do we expect the IMR of non-migrant and U.S.-returned migrant women in Mexico to compare to the IMR of women of Mexican origin in the United States?Women of Mexican origin in the United States have surprisingly low rates of infant mortality, relative to non-Hispanic white and black women (Hummer et al., 1999), as well as relative to non-migrant women in Mexico– This is partially explained by healthy migrant selectivity, both into and out

of the United States• Women migrating to the United States are selectively healthy (Palloni

& Morenoff, 2001)• Women return migrating out of the United States may be a less

healthy sub-group (Pablos-Mendez, 1994; Abraido-Lanza et al., 1999)

Data, Measures and Methods•2000 Mexican Census 10% sample – 907,862 women whose last child was born between 1995 and 2000

•Key outcome measure: survivorship of last child born; if died, age at death less than 12 months•Key independent measures:– Individual-level migration: mother reports living in United States in 1995– Household-level migration:

• One or more household member departed for United States between 1995 and 2000

• Mother reports receiving remittances from abroad– Community-level: proportion of adult community members with recent

(1995-2000) U.S. migration (communities are municipalities)•Controls: mother’s age, mother’s age squared, mother’s marital status, parity, mother’s race, mother’s health insurance, mother’s education, household poverty, rural/urban location, migration region, community poverty

•Two-level hierarchical linear models estimated to account for nested nature of data (women within communities) control for demographic, socioeconomic and geographic characteristics•Models estimated separately for rural and urban samples•We also compare estimated IMR for migrant and non-migrant women in Mexico to IMRs of foreign-born and U.S.-born women of Mexican origin in the U.S.

0

2

4

6

8

10

12

14

16

18

20

Rural Urban

Low

High

Community Migration Prevalence:

Recent Mexican migrants to the United States originate predominantly in the center-west part of the country, pulling the weighted center north-west of Mexico City. There is quite a bit of variation in the municipal levels of recent migration prevalence, although the overall levels are low.

Infant Mortality Rate by Community Migration Prevalence in Rural and Urban Places in Mexico

Model 3Mother's Socio-Demographic Characteristics

Mother's age (years) 0.880 *** 0.880 *** 0.881 ***Mother's age squared 1.003 *** 1.003 *** 1.003 ***Marital status (ref=married) Cohabiting 1.152 *** 1.153 *** 1.151 *** Separated 0.989 0.988 0.988 Divorced 1.181 1.182 1.181 Widowed 0.894 0.894 0.894 Single 1.566 *** 1.565 *** 1.565 ***Parity (ref=low parity) First birth 0.699 *** 0.699 *** 0.699 *** High parity 1.806 *** 1.806 *** 1.806 ***Race Indigenous 0.975 0.976 0.966Health insurance coverage (ref=insured) Uninsured 1.124 *** 1.121 *** 1.123 ***Education (ref=some high school) No education 1.649 *** 1.651 *** 1.652 *** Primary education 1.491 *** 1.491 *** 1.494 *** Junior high education 1.260 *** 1.260 *** 1.260 ***Household Characteristics

Number of people 0.836 *** 0.836 *** 0.836 ***Household poverty index 1.360 *** 1.366 *** 1.360 ***Community Characteristics

Level of urbanization (ref=urban>15000)) Rural (<2500) 1.041 1.039 1.049

Midsized (2500-14999) 1.088 * 1.087 * 1.095 **

Geographic location (ref=historic) Border 0.871 * 0.875 * 0.840 ** Center 1.149 *** 1.154 *** 1.114 ** Periphery 0.939 0.946 0.895 *Community marginality index 1.032 * 1.032 * 1.034 *Migration Experience

Mother is a return migrant 0.575 *** 0.545 *** 0.544 ***Mother receives remittances 0.931 0.936Household has recent migration 1.076 * 1.094 **Community out-migration 0.347 *Level 1 Sample Size 907862 907862 907862Level 2 Sample Size 2442 2442 2442Source: 2000 Mexican Census 10% Sample

* significant at .05; ** significant at .01; *** significant at .001

Entire SampleModel 1 Model 2

Odds ratios predicting likelihood of infant mortality by mother’s, household and community migration experience in Mexico

The infant mortality rate (IMR) is lower in urban places than in rural places in Mexico, regardless of community migration prevalence.In rural places, the IMR is lower in communities with higher levels of recent community migration prevalence.In urban places, the IMR is higher in communities with higher levels of recent community migration prevalence.

-0.8

-0.6

-0.4

-0.2

-0

0.2

0.4

Mother's HH Remittances HH Out-migration

Community

EntireRuralUrban

p<.05p<.01p<.001

How odds ratios for migration measures vary in direction and strength between rural and urban samples (model 3)

Women’s own migration experience is associated with lower odds of infant mortality in all parts of Mexico, although the relationship is strongest in rural places.Remittances are negatively associated with infant mortality in rural places only, whereas one or more recent household trips is positively associated with infant mortality in both rural places and in the entire sample, but not in urban places. Community migration is only significantly associated with lower odds of infant mortality in rural places and the entire sample.

Comparing the IMRs of Mexican Women: Non-migrants and Return Migrants in Mexico versus Immigrant and U.S.-Born Women of Mexican Origin in the United States

Non-migrantReturn

MigrantMexican

ImmigrantU.S. Born of

Mexican Origin12.8 8.4 5.1 6.5

*The Infant Mortality Rate is the number of deaths by oneyear of age per 1000 live births.Source: for Mexico, 2000 Mexican Census; for the United

States, Hummer et al., 2007: Table 3

Mexico United States

The IMR of women of Mexican origin in the United States is lower than the IMR of either non-migrant or return-migrant women in Mexico. Consistent with the odds ratios for women’s own migration experience, the IMR of return migrant women is lower than the IMR of non-migrant women in Mexico.

ConclusionsIndividual, household, and community-level U.S. migration experience associate with individual-level infant mortality, but these relationships differ by level of urbanization.•Recent household and community-level U.S. migration experience are significantly associated with infant mortality in rural, but not in urban, places.

•Household and community-level migration will be associated with infant health because of resources remitted back home, with their impact depending on the sending community context as captured here by level of urbanization.

•Recent individual-level U.S. migration experience is associated with infant mortality in both rural and urban parts of Mexico.

•Individual-level migration is associated with infant health because of healthy migrant selectivity, a process that is not dependent on sending community context.

•However, the IMR of return-migrant women is still higher than that of women of Mexican origin in the United States.

•This is consistent with the salmon bias, a theory that an unhealthy sub-group of migrants return to their place of origin.

•The fact that household-level migration has both beneficial and deleterious relationships with infant health reflects the mixed blessings of migration in rural places: remittances are helpful, but the departure and absence of household members is disruptive. •The greater beneficial impact of remittances and community-level migration in rural places is consistent with our expectations. Because rural households have fewer opportunities and resources than urban households in Mexico, remittances likely make up a larger portion of household resources in rural places, and thus they have a stronger beneficial relationship with infant health in rural places. Community-level migration most likely functions the same way. The developmental potential of migration is greater in rural places because the initial levels of development are lower and the sources of development fewer.

Limitations There are several important limitations to our analysis:•Our estimates of infant mortality are much lower than national and international estimates of the Mexican IMR, for various reasons we’d be happy to discuss.•To identify women migrants, we used information regarding the U.S. location of women in 1995 because we could not accurately merge the individual migration histories with individuals on the household roster. Women may have left Mexico and returned between 1995 and 2000, and we do not capture them with our measure. •We are unable to determine causal relationships with our analysis. Instead, we uncover associations between our various measures of migration, socio-demographic characteristics, and infant mortality.However, we believe these are the only data currently available to conduct this kind of analysis in the Mexican context. Other data sets might facilitate the study of other health outcomes and migration.

IMR