LESSONS LEARNED FROM CROSS-NATIONAL RESEARCH ON MARITAL HOMOGAMY

Albert Esteve and Luis López

Integrated European Census Microdata Project

Centre d’Estudis Demogràfics

Census Microdata: findings and futuresUniversity of Manchester

September 1-3, 2008

Centre d’Estudis DemogràficsUniversitat Autònoma de Barcelona

Discuss the advantages and limitations of carrying out cross-national research on marital homogamy based on census microdata (IPUMS). Lessons learned from my own research on educational and race-ethnic homogamy

Structure of the presentationConcepts, definitions and scientific relevanceAdvantages of using census microdataLimitations of using census microdataConcluding remarks

Main purpose and structure of the presentation

Advantage no. 1 : IPUMS international

dark greendark green = already integrated = already integrated (35 countries, 111 censuses, 263 millon person records)(35 countries, 111 censuses, 263 millon person records)

green = to be integrated (39 countries, 103 censuses, 150 mill.)green = to be integrated (39 countries, 103 censuses, 150 mill.)

IntegratedIntegrated census microdata open to the research community!!!

Advantage no. 1 : IPUMS international

Census Microdata Samples in the Mediterranean Countries2000s 1990s 1980s 1970s 1960s

Albania 2001 1989 1979 1960, 1969Algeria 1998 1987 1977 1966Bosnia-Herzegovina 2001 1991Croatia 2001 1991Cyprus 2001 1992Egypt 2006 1996 1986 1976 1960France 1999 1990 1982 1975 1962, 1968Greece 2001 1991 1981 1970 1960Israel 1995 1983 1972 1961, 1962Italy 2001 1991 1981 1971 1961Jordan 2004 1994 1979Lebanon 1970Libya 1995 1984 1973 1966Macedonia 2002 1991, 1994Malta 2005 1995 1985 1967Morocco 2004 1994 1982 1971 1960Portugal 2001 1991 1981 1970 1960Palestine 2007 1997Serbia Montenegro 1991 1981 1971 1961Sirya 2004 1994 1981 1970 1960Slovenia 2002 1991Spain 2001 1991 1981 1970 1960Tunisia 2004 1994 1984 1975 1966Turkey 2000 1990 1980, 1985 1970, 1975 1960, 1965* In Bold: census microdata surviveSource: Integrated Public Use of Microdata Series international (IPUMS-International), https://international.ipums.org/international/microdata_inventory.html

Advantage no. 2 : sample densities and coverage

n %Brazil 2000Asians 40667 0,40Indigenous 40952 0,41

Chile 2002Mapuche 37370 4,03Aimara 2580 0,28Atacameño 1160 0,13Other 1100 0,12

Ecuador 2001Mulato 14330 2,61Black 11670 2,18Other 1830 0,34

Mexico 2000Indigenous 293080 5,05

Unions of men and women aged 30 – 39 that belong to a minority group that represents less than 5% of the total

population

Advantage no. 3 : persons in households

SAMPLE HHid URBAN PERNUM SPLOC AGE SEX MARST RELIGION SCH YRS ACTIVITY

South Africa 2001 386 Urban 1 2 44 Male Married Christian No 12 EmployedSouth Africa 2001 386 Urban 2 1 40 Female Married Christian No 12 InactiveSouth Africa 2001 386 Urban 3 - 24 Female Single Christian No 12 EmployedSouth Africa 2001 386 Urban 4 - 23 Female Single Christian No 12 UnemployedSouth Africa 2001 386 Urban 5 - 16 Male Single Christian Yes 9 InactiveSouth Africa 2001 386 Urban 6 - 12 Female Single Christian Yes 8 NIUSouth Africa 2001 386 Urban 7 - 10 Female Single Christian Yes 6 NIU

*HHid, Household Identifier*PERNUM, person number*SPLOC, spouse location*MARST, marital status*SCH, school attendance*YRS, years in school*ACTIVITY, activity status

Using SPOUSE LOCATION, we can Using SPOUSE LOCATION, we can easily match all characteristics of the easily match all characteristics of the

spouses reported in the census!!!spouses reported in the census!!!

And the IPUMS extraction system And the IPUMS extraction system does it systematically!!!!!!!does it systematically!!!!!!!

Advantage no. 4 : multiple dimensions of homogamy

Spouse no. 1 Spouse no. 2

SEX Male Female

AGE 44 40

Religion Christian Christian

Education Secondary completed Secondary Completed

Occupation

Race and ethnicity

Place (region or country of birth)

and others....

South Africa 2001, household no. 386

-2

-1

0

1

2

3

4

5

6

7

< 4 4 -7 8 - 10 11 - 14 >= 15

1970 1980 1991 2000

Homogamous marriages are favored and are increasing at higher levels of educational attainment over time.

Log odds for homogamous pairings by level of schooling and census year, Brazil

In Union

Not in Union

Spouse absent

Spouse present

Consensual Union

Marriage

Consensual Union

Marriage

IN UNION SPOUSE PRESENCE TYPE OF UNION PLACE TIME

Country

Abroad

Country

Abroad

After migration

Before migration

After migration

Country

Abroad

Country

Abroad

CENSUS CENSUS

Advantage no. 5 : complete universe of unions

Advantage no. 6 : hierarchical analysis

• Most often, datasets are organized in hierarchichal way: – Individuals– Households– Region– Country

• This makes multilevel modeling possible. Independent variables can be incorporated at any level

• Surprisingly, samples for some developed countries do not use this sample design.

Advantage no. 6 : hierarchical analysis

Dependent Variable : Educational Homogamy

Independent Variables

Contextual Effects

SEXRATIO: Log transformation of the number of educational group members of the opposite sex divided by the number of group members of the same sex by region of residence

GROUPSIZE: Log transformation of the relative educational group size at the regional level

ETHNIC / RACE / BIRTHPLACE SIMILARITY: Percentage of the educational group that have the same race-ethnicity/birthplace country

Individual Effects

SEX

EDUCATION: Based on IPUMSI “Educational Attainment”

RACE / ETHNICITY / BIRTHPLACE

Argentina Brazil

Ecuador Mexico

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

0,0 0,2 0,4 0,6 0,8 1,0

Birthplace Similarity

Od

ds

Ra

tio

0,0

2,0

4,0

6,0

8,0

10,0

12,0

0,0 0,2 0,4 0,6 0,8 1,0

Race Similarity

Odd

s R

atio

0,0

0,5

1,0

1,5

2,0

2,5

3,0

3,5

4,0

4,5

5,0

0,0 0,2 0,4 0,6 0,8 1,0

Race Similarity

Odd

s R

atio

0,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0

9,0

0,0 0,2 0,4 0,6 0,8 1,0

Ethnic Similarity

Odd

s R

atio

Less than Primary Primary Completed Secondary Completed University Completed

Advantage no. 6 : hierarchical analysis

Effect of Race-ethnic similarity in educational homogamy by level of educational attainment

Censuses only capture current unions and not all unions prevail

Separation Divorce Widowhood Remarriage

Is the likelihood of union dissolution equal for all types of unions?

Limitation no. 1 : only prevailing unions

Limitation no. 1 : only prevailing unions

0,0

0,2

0,4

0,6

0,8

1,0

1,2

1,4

1,6

1,8

Homogamy Hypergamy

25-29 35-39 46-50

Brazil, women born 1945 – 49 (log odds ratio)

Do homogamy and hypergamy levels change for the same cohort at different ages?

Limitation no. 2 : only co-residing partners

Country Percentage

Argentina 2001 2.4%

Brazil 2000 2.2%

Chile 2002 2.4%

Costa Rica 2000 2.6%

Ecuador 2001 1.8%

México 2000 1.7%

Proportion of married individuals with spouse absent

When did they get married? When was the union formed?

What were the individual’s characteristics at the time of marriage?

Is this the first time they marry?

Where did they get married?

What was the parents’ educational attainment?

Limitation no. 3 : cross-sectional data with little biographical information

Limitation no. 4 : international comparability

Concluding remarks

Availability of international census microdata offers an unprecedented opportunity to carry out cross-national research on marital homogamy and other topics

Most of developing countries have census microdata samples

There are obvious limitations (prevalence, co-residing partners, cross-sectional data), that can be overcome by restricting the analysis to certain types of unions

The most important challenge is to obtain meaningful results for the countries individually and in comparative perspective

Thanks!!!

Albert Esteve aesteve@ced.uab.es

Census Microdata: findings and futuresUniversity of Manchester

September 1-3, 2008

Centre d’Estudis Demogràfics Universitat Autònoma de Barcelona