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Research Topics> My contributions to Sex Ratio analysis

Sex ratios are the ratios of men to women (or vice-versa). The convention in demography is to place men in the numerator. From the perspective of a marriage market analysis sex ratio imbalances have many consequences. High ratios of males make it easier for women to marry, but harder for men, a situation that has been called ‘marriage squeeze for men’. In contrast low sex ratios lead to marriage squeezes for women. Sociologists and demographers wrote on the consequences of marriage squeezes as early as 1957. Their focus was on marriage rates. In his theory of marriage Gary Becker (1973) predicted that sex ratio imbalances would affect individual consumption and leisure of husbands and wives. I am the first to have linked these imbalances to changes in the labor supply of the women in general, and married women in particular.

Sex ratios and labor supply

Theory. I first generated theoretical predictions regarding the effect of marriage squeezes on labor supply in Grossbard-Shechtman 1984. This model was expanded and explained more clearly in my 2015 book The Marriage Motive. A telegraphic version of the theory appeared in Heer and Grossbard-Shechtman (1981) where we also present some evidence.

Evidence. Sex ratios vary across cities, regions and other geographical units. However, testing for sex ratio effects across cities brings up a problem of reverse causality: women may migrate to cities with more job opportunities for women, and men to where men have more good jobs. The most reliable evidence on how sex ratios affect a variety of outcomes is based on natural experiments such as exogeneous changes in sex ratio as a result of wars, changes in cohort size, immigration flows or incarceration rates. I have done some pioneering empirical work using exogeneous cohort-based fluctuations in sex ratio.

In Heer and Grossbard-Shechtman (1981)  we documented how the first cohort of baby-boom women were experiencing numerous consequences of marriage squeezes for women, including rapid labor supply increases. We compared trends in sex ratio to trends in women’s labor force participation and found that in the late sixties and early seventies sex ratios for young women had gone down rapidly, as large numbers of women born after the war found relatively few marriageable men a bit older and born during the war. For example, in 1956 the sex ratio was balanced but 9 years later, in 1965, there were 11 missing men for every 100 women ages 17 to 24 due to the baby-boom that started in 1937 after the New Deal was instituted. A larger baby-boom started in 1946. We find that from 1960 to 1975 labor force participation rates of married women aged 20-24 rose from 31.7 percent to 57.0 percent, implying that rapid drops in sex ratio were accompanied by unprecedented growth in young married women’s labor force participation. This article is often cited, often jointly with a book by Guttentag and Secord (1983) that was published later, made many of the same points and obtained sociology prizes.

Sex ratios vary by birth cohort because (1) on average, women marry men who are generally somewhat older and the age difference does not fluctuate much, and (2) the number of births fluctuates from one birth cohort to the next. For example, in the early 1950s there were more marriageable men than women—i.e. marriage squeezes for men--in many Western countries as a result of declining numbers of births following the 1929 Depression. Conversely, in the mid-1960s in the United States and other countries who experienced a baby boom after World War II, when the first baby-boomers started dating, baby-boom women experienced marriage squeezes. 

In Grossbard-Shechtman (1985) I used the first twenty years of CPS data to simply compare time trends in sex ratio (as defined in Heer and Grossbard-Shechtman 1981) with trends in percent of women employed at ages 25-34. Graphs made it clear that the plunge in sex ratio experienced by first baby-boomers born after World War II—the cohort with the largest marriage squeeze for women-- corresponds to a striking rise in young women’s employment about thirty years later. By the late 1970s and early 1980s young women’s employment surge stopped.  By then later baby-boomers had entered labor and marriage markets. They experienced smaller marriage squeezes as a result of the decreasing rate at which fertility grew in the 1950s. In the 1980s I predicted that cohorts of women born after 1960 (what I call baby-bust cohorts) would experience a slowdown or a reversal in the rate at which women entered the labor force. I expected the drop in rate of women’s labor force participation to be especially pronounced when those born in the early 1970s around the passage of Roe vs. Wade would enter marriage and labor markets.

By the 1990s the CPS series was long enough to enable tests of my predictions. This led to Grossbard-Shechtman and Granger (1998) co-authored with Nobel prize winner Clive Granger and the only article authored by a Nobel prize winner that was ever published in the French journal Population (the link is to an English translation!). We used data for 1965-1990, controlled for other factors that changed over time, and showed that women born in cohorts with lower sex ratios experienced more rapid growth in labor supply than women from other birth cohorts. By 2000, as further cohorts of baby-bust women were entering the labor and marriage markets, I was curious to see whether there would be further slowdowns—and perhaps reversals---in the rate at which young women participated in the labor force. In Grossbard-Shechtman 2000 I report that between 1998 and 1999 the participation rate of young married women ages 25 to 34 experienced its largest decrease since the end of World War II. This was in line with my sex ratio analysis: women born between 1964 and 1973 were part of a baby-bust that later led to a marriage squeeze for men. The squeeze was leading men to work harder (their labor supply increased between 1998 and 1999) and women to work less hard than did preceding cohorts experiencing marriage squeezes for women.

Employment data for the period 1965-2005 and for women between ages 25 to 44 were analyzed in my 2007 paper with Catalina Amuedo-Dorantes,  "Marriage Markets and Women's Labor Force Participation. We covered cohorts of women born between 1926 and 1980, a set of cohorts exhibiting major fluctuations in sex ratio due to the sequence of baby-bust, baby-boom, baby-bust that followed the baby-boom, and echo of the Post World War II baby boom. We used CPS data for five-year groups and four regions, and found that cohorts of women with lower sex ratios (women born at the onset of the baby-boom) had experienced above-average labor force participation whereas cohorts of women with higher sex ratios (born at the beginning of baby-busts) had experienced below-average labor force participation. Drops in young married women’s labor force participation rates could be explained by the relatively high sex ratios observed for women born during the baby-bust. Results held for married women and for all women (including both married and unmarried women) and were robust to the inclusion of women’s wages, education, and presence of young children in the regression models. Including these variables weakened the sex ratio effects, but did not wipe them out.  An increase in sex ratio of .10 has the same effect on young women’s labor force participation rate as two more years of schooling, which is very significant.

In 2006, as a result of this research I made predictions regarding the labor supply of women born during the echo of the Post World War II baby-boom, those born after 1977 who had recently entered the labor and marriage markets when observed in 2005. Given that these echo women would be experiencing marriage squeezes for women, in contrast to the baby-busters who were benefiting from marriage squeezes for men, I predicted future increases in women’s labor force participation rate: “By the time most echo women will be having their first child, around 2015, we may observe another reversal in women’s labor force participation.” (Grossbard 2006). In November 2015 the labor force participation of women ages 30 to 54 increased relative to the previous month, which is consistent with the prediction made nine years earlier. This upward trend may indicate that we are entering a new period of rising women’s labor force participation, as I argued on Forbes/opinion (Grossbard 2016).

Becker, Gary S. 1973. "A Theory of Marriage: Part I." Journal of Political Economy 81:813-846.
Guttentag, Marcia and Secord, Paul F. (1983), Too Many Women: The Sex Ratio Question. Beverly Hills: Sage Publications.

List of my publications on sex ratios and labor supply (many of which are not mentioned above)

Sex ratios and other outcomes

Savings. The prediction that sex ratios will affect savings rates is found in Chapter 11 in the Marriage Motive (add link here). An earlier version of the model developed with Alfredo Pereira Will_Women_Save_More_Than_Men_A_Theoretical_Model_of_Savings_and_Marriage also included sex ratio effects.

Other outcomes.
In my publications I have analyzed how sex ratios may affect or actually affected marriage rates, non-marital cohabitation, use of contraceptives, women’s education, the onset of the feminist revolution, choice between common law and regular marriage in the US, bride price and dowry, intermarriage between blacks and whites, intermarriage between Jews and Gentiles, passage of no-fault divorce laws, spouse’s education and age, polygyny, fertility, investments in children and perhaps some more..

Partial List of publications (contact me if you need help)

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