Changes In Assortative Mating Research Articles

Structural opportunities or assortative mating? – Decomposing trends and country differences in educational sorting outcomes in marriages

ABSTRACT This study examines within- and cross-country trends and differences in marital sorting by education in Europe. Unlike previous research on assortative mating, our study focuses on the outcomes of the partner search process. We investigate how variations in (a) structural opportunities (educational composition of potential partners) and (b) assortative mating (non-random matching by education) have shaped trends and differences in educational sorting outcomes. Using vital statistics data on all marriages contracted from 2000 to 2020 in Sweden, the Czech Republic, and Italy, we decompose trends and differences in educational sorting outcomes into these two components. Within countries, trends in educational homogamy and hypogamy have been stable or increasing while hypergamy has declined. However, the drivers of these trends varied across countries. For example, in Sweden, shifts in assortative mating and structural opportunities led to more marriages between equally educated spouses, while in Italy, the rise in homogamy stems solely from changes in assortative mating. Within each year, homogamy and heterogamy levels varied between countries. Our findings demonstrate that these cross-country differences can be primarily attributed to variations in assortative mating rather than in opportunity structures. This study adds to recent research studying the structural causes of trends in sorting outcomes.

Pathways toward Inclusive Income Growth: A Comparative Decomposition of National Growth Profiles

Despite rising interest in income inequality, scholars remain divided over the mechanisms underlying inclusive income growth and how these mechanisms vary across countries. This study introduces the concept of national growth profiles, that is, the additive contribution of changes in taxes, transfers, composition, and other factors including market institutions to changes across a country’s income distribution. We present a decomposition framework to measure national growth profiles for eight high-income countries from the 1980s to 2010s. Our findings adjudicate competing sociological and economic perspectives on rising inequality. First, we find that policy-driven changes in taxes and transfers are the dominant drivers of inclusive growth at the tails of the income distributions. Second, rising educational attainment contributes most to income growth across the distribution, but consistently contributes to less-inclusive growth. When changes in education are considered, changes in assortative mating and single parenthood have little consequence for changes in inequality. Third, changes to other factors including market institutions increased inequality in countries such as the United States, but less so in France and Germany. Had the United States matched the changes to Dutch tax policy, Danish transfer policy, or other factors of most other countries, it could have achieved more inclusive income growth than observed.

Marriage Market Counterfactuals Using Matching Models

We use a simple structural matching model with unobserved heterogeneity to produce counterfactual marriage patterns, and thus quantify the contribution of changes in marital patterns in rising income inequality. We propose an algorithm that allows us to fix the degree of assortative mating without changing the level of marital gains and hence isolate the intensive and extensive margins (i.e. isolate changes in assortative mating from changes in marriage rates). We apply this approach to US data from 1962 to 2017, and show that marital patterns can explain about a quarter of the rise in income inequality, the intensive margin contributing 7%, the extensive margin the remaining 93%. Our algorithm also allows us to show that the extensive margin is itself driven for three‐fifths by a change in the total number of singles and for two‐fifths by a change in the distribution of types among singles (in particular low‐educated women).

Changes in Couples' Earnings Following Parenthood and Trends in Family Earnings Inequality.

The growing economic similarity of spouses has contributed to rising income inequality across households. Explanations have typically centered on assortative mating, but recent work has argued that changes in women’s employment and spouses’ division of paid work have played a more important role. We expand this work to consider the critical turning point of parenthood in shaping couples’ division of employment and earnings. Drawing on three U.S. nationally representative surveys, we examine the role of parenthood in spouses’ earnings correlations between 1968 and 2015. We examine the extent to which changes in spouses’ earnings correlations are due to (1) changes upon entry into marriage (assortative mating), (2) changes between marriage and parenthood, (3) changes following parenthood, and (4) changes in women’s employment. Our findings show that increases in the correlation between spouses’ earnings prior to 1990 came largely from changes between marriage and first birth, but increases after 1990 came almost entirely from changes following parenthood. In both instances, changes in women’s employment are key to increasing earnings correlations. Changes in assortative mating played little role in either period. An assessment of the aggregate-level implications points to the growing significance of earnings similarity after parenthood for rising income inequality across families.

The role of partnering and assortative mating for income inequality: The case of Finland, 1991–2014

Previous studies covering various developed countries suggest that changes in assortative mating by education have contributed only a little to the changes in income inequality, opposite to the expectations of many. In this paper we consider two potential reasons for the zero effects: (a) that it is the selection into partnership rather than assortative mating according to specific characteristics that matters; and (b) that for assortative mating to matter, a broader spectrum of matching characteristics than just education should be considered, such as matching by employment and social origin. We study these assumptions using register data on household income inequalities, education, employment and parental class background in Finland 1991–2014. We analyze men and women separately and focus on individuals aged 35–40. We concentrate on between-group income inequality as measured by the Theil index. The results suggest that partnership is an important factor behind income inequality, and changes in selection into partnership can explain a substantial part of the changes in income inequality. Assortative mating does not matter as much, even if more sorting characteristics are taken into account. Social origin contributes very little to the income inequality of families in Finland

Parental Skills, Assortative Mating, and the Incidence of Autism Spectrum Disorder

We use rich administrative data from Denmark to assess medical theories that autism spectrum disorder (ASD) is a heritable condition transmitted through underlying parental skills. Positing that occupational choices reflect skills, we create two separate occupation-based skill measures and find that these measures are associated with ASD incidence among children, especially through the father's side. We also assess the empirical relevance of assortative mating based on skill, concluding that intertemporal changes in assortative mating explain little of the increase in ASD diagnoses in recent decades.

Changes in Assortative Matching and Inequality in Income: Evidence for the UK*

AbstractThe extent to which like‐with‐like marry is important for inequality as well as for the outcomes of children who result from the union. In this paper, we present evidence on changes in assortative mating and its implications for household inequality in the UK. Our approach contrasts with others in the literature in that it is consistent with an underlying model of the marriage market. We argue that a key advantage of this approach is that it creates a direct connection between changes in assortativeness in marriage and changes in the value of marriage for the various possible matches by education group. Our empirical results do not show a clear direction of change in assortativeness in the UK between the birth cohorts of 1945–54 and 1965–74. We find that changes in assortativeness pushed income inequality up slightly, but that the strong changes in education attainment across the two cohorts contributed to scale down inequality.

Changes in Assortative Matching: Theory and Evidence for the US

The extent to which like-with like marry is particularly important for inequality as well as for the outcomes of children that result from the union. In this paper we discuss approaches to the measurement of changes in assortative mating. We derive two key conditions that a well-defined measure should satisfy. We argue that changes in assortativeness should be interpreted through a structural model of the marriage market; in particular, a crucial issue is how they relate to variations in the economic surplus generated by marriage. We propose a very general criterion of increase in assortativeness, and show that almost all indices used in the literature are implied by our criterion with one notable exception, that moreover violates one of our conditions. Finally, we use our approach to evaluate the evolution of assortative matching in the US over the last decades, and conclude that assortative matching has increased, particularly at the top of the education distribution. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Changes in Assortative Matching and Inequality in Income: Evidence for the UK

The extent to which like-with like marry is important for inequality as well as for the outcomes of children that result from the union. In this paper we present evidence on changes in assortative mating and its implications for household inequality in the UK. Our approach contrasts with others in the literature in that it is consistent with an underlying model of the marriage market. We argue that a key advantage of this approach is that it creates a direct connection between changes in assortativeness in marriage and changes in the value of marriage for the various possible matches by education group. Our empirical results do not show a clear direction in the change in assortativeness in the UK, between the birth cohorts of 1945-54 and 1965-74. We find that changes in assortativeness pushed income inequality up slightly, but that the strong changes in education attainment across the two cohorts contributed to scale down inequality. Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Changes in Assortative Matching: Theory and Evidence for the Us

The extent to which like-with like marry is particularly important for inequality as well as for the outcomes of children that result from the union. In this paper we discuss approaches to the measurement of changes in assortative mating. We derive two key conditions that a well-defined measure should satisfy. We argue that changes in assortativeness should be interpreted through a structural model of the marriage market; in particular, a crucial issue is how they relate to variations in the economic surplus generated by marriage. We propose a very general criterion of increase in assortativeness, and show that almost all indices used in the literature are implied by our criterion with one notable exception, that moreover violates one of our conditions. Finally, we use our approach to evaluate the evolution of assortative matching in the US over the last decades, and conclude that assortative matching has increased, particularly at the top of the education distribution.

A meta-analysis of whole genome duplication and theeffects on flowering traits in plants.

Polyploidy, or whole genome duplication (WGD), is common in plants despite theory suggesting that polyploid establishment is challenging and polyploids should be evolutionarily transitory. There is renewed interest in understanding the mechanisms that could facilitate polyploid establishment and explain their pervasiveness in nature. In particular, premating isolation from their diploid progenitors is suggested to be a crucial factor. To evaluate how changes in assortative mating occur, we need to understand the phenotypic effects of WGD on reproductive traits. We used literature surveys and a meta-analysis to assess how WGD affects floral morphology, flowering phenology, and reproductive output in plants. We focused specifically on comparisons of newly generated polyploids (neopolyploids) and their parents to mitigate potential confounding effects of adaptation and drift that may be present in ancient polyploids. The results indicated that across a broad representation of angiosperms, floral morphology traits increased in size, reproductive output decreased, and flowering phenology was unaffected by WGD. Additionally, we found that increased trait variation after WGD was uncommon for the phenotypic traits examined. Our results suggest that the phenotypic effects on traits important to premating isolation of neopolyploids are small, in general. Changes in flowering phenology, reproductive output, and phenotypic variation resulting from WGD may be less critical in facilitating premating isolation and neopolyploid establishment. However, floral traits for which size is an important component of function (e.g., pollen transfer) could be strongly influenced by WGD.

Educational Assortative Mating and Household Income Inequality

We investigate the pattern of educational assortative mating, its evolution over time, and its impact on household income inequality. To these ends, we use rich data from the United States and Norway over the period 1980-2007. We find evidence of positive assortative mating at all levels of education in both countries. However, the time trends vary by the level of education: Among college graduates, assortative mating has been declining over time, whereas individuals with a low level of education are increasingly sorting into internally homogenous marriages. When looking within the group of college educated, we find strong but declining assortative mating by academic major. These findings motivate and guide a decomposition analysis, where we quantify the contribution of various factors to the distribution of household income. We find that educational assortative mating accounts for a non-negligible part of the cross-sectional inequality in household income. However, changes in assortative mating over time barely move the time trends in household income inequality. The reason is that the decline in assortative mating among the highly educated is offset by an increase in assortative mating among the less educated. By comparison, increases in the returns to education over time generate a considerable rise in household income inequality, but these price effects are partly mitigated by increases in college attendance and completion rates among women.

Education and marriage: the shift from female hypergamy to hypogamy in Belgium, a 20th century cohort analysis

One of the key social trends of the 20th century has been the expansion of participation in education. Using detailed retrospective information from the 1981 and 2001 censuses, this paper investigates how this expansion is associated with major trends in nuptiality in Belgium. We focus specifically on the changing gender balance in education and how this is related to the likelihood and timing of marriage and to patterns of educational assortative mating. Our empirical analysis shows that marriage was getting more universal, happening at an earlier age and more often heterogamous in term of education over the cohorts born in the first half of the 20th century. In younger cohorts, when women’s levels of education caught up with men’s, the age at marriage as well as the degree of homogamy increased again. Homogamy remained dominant throughout, but while women tended to marry men who were at least as highly educated as themselves until the 1950s cohorts, in more recent cohorts, women have tended to marry men who are at most as highly educated as themselves. Hypogamy is now the second most common pattern, after homogamy. Controlling for changes in the distribution of educational attainment by applying a log-linear model, we find that part of the changes in assortative mating in Belgium may be explained by changes in mate preferences regarding education. Finally, we find that hypogamous marriages tend to be contracted at later ages than homogamous or hypergamous ones.

Women's Progress for Men's Gain? Gender-Specific Changes in the Return to Education as Measured by Family Standard of Living, 1990 to 2009-2011.

This study investigates gender-specific changes in the total financial return to education among persons of prime working ages (35-44 years) using U.S. Census data from 1990 and 2000, and the 2009-2011 American Community Survey. We define the total financial return to education as the family standard of living as measured by family income adjusted for family size. Our results indicate that women experienced significant progress in educational attainment and labor market outcomes over this time period. Ironically, married women's progress in education and personal earnings has led to greater improvement in the family standard of living for married men than for women themselves. Gender-specific changes in assortative mating are mostly responsible for this paradoxical trend. Because the number of highly educated women exceeds the number of highly educated men in the marriage market, the likelihood of educational marrying up has substantially increased for men over time while women's likelihood has decreased. Sensitivity analyses show that the greater improvement in the family standard of living for men than for women is not limited to prime working-age persons but is also evident in the general population. Consequently, women's return to education through marriage declined while men's financial gain through marriage increased considerably.

Trends in Economic Homogamy: Changes in Assortative Mating or the Division of Labor in Marriage?

The growing economic resemblance of spouses has contributed to rising inequality by increasing the number of couples in which there are two high- or two low-earning partners. The dominant explanation for this trend is increased assortative mating. Previous research has primarily relied on cross-sectional data and thus has been unable to disentangle changes in assortative mating from changes in the division of spouses' paid labor-a potentially key mechanism given the dramatic rise in wives' labor supply. We use data from the Panel Study of Income Dynamics (PSID) to decompose the increase in the correlation between spouses' earnings and its contribution to inequality between 1970 and 2013 into parts due to (a) changes in assortative mating, and (b) changes in the division of paid labor. Contrary to what has often been assumed, the rise of economic homogamy and its contribution to inequality is largely attributable to changes in the division of paid labor rather than changes in sorting on earnings or earnings potential. Our findings indicate that the rise of economic homogamy cannot be explained by hypotheses centered on meeting and matching opportunities, and they show where in this process inequality is generated and where it is not.

Educational Assortative Mating and Household Income Inequality

We document the degree of educational assortative mating, how it evolves over time, and the extent to which it differs between countries. Our analysis focuses on the United States but also uses data from Denmark, Germany, the United Kingdom, and Norway. We find evidence of positive assortative mating at all levels of education in each country. However, the time trends vary by the level of education: Among college graduates, assortative mating has been declining over time, whereas individuals with a low level of education are increasingly sorting into internally homogeneous marriages. These findings motivate and guide a decomposition analysis, where we quantify the contribution of various factors to the distribution of household income. We find that educational assortative mating accounts for a non-negligible part of the cross-sectional inequality in household income in each country. However, changes in assortative mating over time barely move the time trends in household income inequality. This is because the inequality contribution from the increase in assortative mating among those with lower levels of education is offset by the equalizing effect from the decline in assortative mating among the highly educated. By comparison, increases over time in the returns to education generate a considerable rise in household income inequality, but these price effects are partly mitigated by increases in college attendance and completion rates among women.

The Dynamics of Assortative Mating in Germany

This paper examines the patterns of educational assortative mating in East and West Germany. In the literature it is well known that individuals do not mate randomly with respect to social and cultural traits, and that highly assortative mating can lead to polarization and exacerbate economic inequality. For Germany, little is known about actual patterns of marriage formation along educational lines. Our empirical analysis for Germany shows that educational assortative mating has increased significantly for East and West Germany during the last 15 and 30 years, respectively. To control for secular increases in educational attainment we apply different log-linear methods, leading to the conclusion that the observed changes in assortative mating in East and West Germany might be explained by changes in partner preferences. Especially within the group of low educated persons, the preferences for a homogamous partnership seems to have increased over time.

A semiparametric analysis of the rising breadwinner role of women in the UK

This paper describes the changes in the relative position of women in the family—as measured by their share of household labour income—in the UK between 1994 and 2004. Using a methodology that borrows from DiNardo et al. (Econometrica 64:1001–44, 1996), it assesses the contribution of changes in men’s and women’s characteristics, the market returns to these characteristics and the role of assortative mating. The main factor which accounts for the increase in the relative female earnings share is the rising female labour force participation across the whole distribution of the female breadwinner index. Changes in assortative mating have a modest positive impact on the index at the mean, 25th and 75th percentiles of the distribution. This is explained by increasing positive assortative mating between 1994 and 2004.

Inequality decomposition by factor component: a “rank-correlation” approach illustrated on the Taiwanese case

SummaryThis paper systematises the method initiated by Burtless (1999) and provides a general framework for decomposing inequality by factor components. It has the double advantage over usual decomposition procedures to allow for a decomposition of changes in the whole income distribution and to distinguish between the effect of marginal distribution changes of income sources and that of changes in correlation between income sources. An illustration is provided for Taiwan, which emphasises the central role played by changes in assortative mating of spouses.

Social and Political Assortative Mating in Urban China

Using survey data from urban China, the rigidity of the status hierarchy and the importance of status-group boundaries in the process of mate selection are explored. Specifically, the patterns of assortative mating by sociopolitical characteristics are examined. Statistical analyses show three important findings. First, the log-linear models uniformly indicate that, despite a strong tendency toward status homogamy, urban Chinese couples are also mismatched symmetrically. Second, when mismatches occur, marriage prospects tend to marry partners from adjacent status groups. Third, although the systems of union formation and status hierarchies have undergone enormous transformations since 1949, the “crossing models” do not reveal parallel and significant changes in assortative mating. It is concluded that neither the socialist transformation in the 1950s and the Cultural Revolution in the 1960s nor the recent economic reforms have changed the patterns of assortative mating in urban China. Status homogamy remains a dominant social norm and practice.