Skewed Sex Ratios at Birth and Future Marriage Squeeze 83 census,and it has only marginally increased since then.Jones (2007:466)attributed these features to both institutional and structural factors.Among men,the average age at first marriage was 25.1 years and has remained constant over the last two decades.However,because the experience of neighboring countries,such as South Korea and Japan,suggests that female age at marriage may rise in the future,I have also postulated a gradual increase in age at marriage among Chinese women up to 26.5 years in 2050,a pace of change comparable to that hypothesized for India.It may be observed that the projected female age at first marriage for China in 2050 remains significantly below the current figures for Japan and South Korea,where women today marry,on average,at age 29. Alterative Marriage Models The modified FD model corresponds to a reasonable scenario of future marriages based on both nuptiality changes among Asian women and a strictly parallel rise in male nuptiality.Yet,this system allows for almost no flexibility in marriage patterns since both female and male marriage schedules are fixed.In this section,I relax some of these assumptions and explore two alternative ways in which the marriage market may adjust to gender imbalances,mostly through a gradual increase in the age difference between spouses caused either by earlier female marriages or by delayed male marriages(methods and parameters are in Appendix B). One possible change corresponds to symmetrical changes in male and female marriage schedules.This is the harmonic mean(HM)model,which is probably the most commonly used marriage matching function(Schoen 1981;see also Okun 2001;Qian and Preston 1993;and Raymo and Iwasawa 2005).This method provides the basis for a self-regulatory marriage system in the case of imbalances,such that the surplus sex is assumed to temporarily defer marriage while the deficit sex is expected to marry earlier.At the same time,the average age at first marriage of the combined male and female cohorts remains the same.The HM model implies that the deficit sex takes advantage of the relative surplus of the opposite sex by marrying earlier because its pool of prospective spouses has momentarily expanded.In other words,union is regarded as partly constrained by the number of suitable partners,and marriage probabilities are expected to rise when the relative size of the unmarried population of the opposite sex increases.Because union has long been nearly universal among women in China and India,there is no pool of available unmarried women,and the application of the HM model entails a reduction in female age at marriage.Such an adjustment may be conceivable if current constraints on marriage-such as intense dowry negotiations in India or prohibition of early marriage in China-were relaxed. Similarly,the abundance of marriageable men could also improve the probability of women finding suitable partners by shortening the search period.2 I also use a different model that combines features from the FD model (rising female age at marriage)and the HM model(rising age difference).In this hybrid model based on delayed male marriage (DMM),I posit a regular increase in female I am grateful to the suggestion of an anonymous reviewer on this point. Better marriage opportunities for women and lower dowry costs in high sex-ratio societies are among the hypotheses put forward by Guttentag and Secord(1983). ②Springercensus, and it has only marginally increased since then. Jones (2007:466) attributed these features to both institutional and structural factors. Among men, the average age at first marriage was 25.1 years and has remained constant over the last two decades. However, because the experience of neighboring countries, such as South Korea and Japan, suggests that female age at marriage may rise in the future, I have also postulated a gradual increase in age at marriage among Chinese women up to 26.5 years in 2050, a pace of change comparable to that hypothesized for India.11 It may be observed that the projected female age at first marriage for China in 2050 remains significantly below the current figures for Japan and South Korea, where women today marry, on average, at age 29. Alternative Marriage Models The modified FD model corresponds to a reasonable scenario of future marriages based on both nuptiality changes among Asian women and a strictly parallel rise in male nuptiality. Yet, this system allows for almost no flexibility in marriage patterns since both female and male marriage schedules are fixed. In this section, I relax some of these assumptions and explore two alternative ways in which the marriage market may adjust to gender imbalances, mostly through a gradual increase in the age difference between spouses caused either by earlier female marriages or by delayed male marriages (methods and parameters are in Appendix B). One possible change corresponds to symmetrical changes in male and female marriage schedules. This is the harmonic mean (HM) model, which is probably the most commonly used marriage matching function (Schoen 1981; see also Okun 2001; Qian and Preston 1993; and Raymo and Iwasawa 2005). This method provides the basis for a self-regulatory marriage system in the case of imbalances, such that the surplus sex is assumed to temporarily defer marriage while the deficit sex is expected to marry earlier. At the same time, the average age at first marriage of the combined male and female cohorts remains the same. The HM model implies that the deficit sex takes advantage of the relative surplus of the opposite sex by marrying earlier because its pool of prospective spouses has momentarily expanded. In other words, union is regarded as partly constrained by the number of suitable partners, and marriage probabilities are expected to rise when the relative size of the unmarried population of the opposite sex increases. Because union has long been nearly universal among women in China and India, there is no pool of available unmarried women, and the application of the HM model entails a reduction in female age at marriage. Such an adjustment may be conceivable if current constraints on marriage—such as intense dowry negotiations in India or prohibition of early marriage in China—were relaxed. Similarly, the abundance of marriageable men could also improve the probability of women finding suitable partners by shortening the search period.12 I also use a different model that combines features from the FD model (rising female age at marriage) and the HM model (rising age difference). In this hybrid model based on delayed male marriage (DMM), I posit a regular increase in female 11 I am grateful to the suggestion of an anonymous reviewer on this point. 12 Better marriage opportunities for women and lower dowry costs in high sex-ratio societies are among the hypotheses put forward by Guttentag and Secord (1983). Skewed Sex Ratios at Birth and Future Marriage Squeeze 83