Skewed Sex Ratios at Birth and Future Marriage Squeeze 79 cohorts stems also from long-term trends:the number of annual births tends to increase during the first phase of the demographic transition but decreases later after prolonged fertility decline.India's case is probably emblematic of this situation because the number of births recorded a regular increment until 1990.For instance, the annual increase in the birth cohort size reached 1.5%during the 1970s.This means that there were,on average,7.7%more prospective wives born during this decade than husbands born five years earlier (five years being the current age difference at marriage),and this imbalance affected the marriage market 20 years later.Incidentally,this disequilibrium in the past is often associated with the concomitant rise in dowry observed in India after independence (Mari Bhat and Halli 1999).But with decreases in fertility and further changes in age structures,the number of births started declining in the 1990s,and,according to my population projections,this reduction in the size of birth cohorts is expected to accelerate in the future.For instance,by 2025,an average birth cohort in a given year would be 7% larger than the cohort born five years later.Without any rise in the SRB,male adults would therefore become more numerous than their prospective brides. China presents an undoubtedly more complicated picture because of the irregular size of its birth cohorts since the 1950s.While the number of births has,on the whole,decreased since the 1980s,this decline is less rapid than in India and also is disturbed by the regular ups and downs that are a legacy of China's volatile demographic past.Short-term fluctuations therefore have a marked effect on age and sex distributions in China and will directly influence the sex ratio of adults-a point highlighted by Goodkind(2006)and Rallu(2006).But the decline in the number of births will also be pronounced in China,especially during 2020-2035.3 As a result, the impact of skewed SRBs in China and India on adult sex ratios is likely to be compounded by future age-structural transformations.I therefore insert a separate projection set designed to assess the potential influences of changes in age structures on marriage imbalances. Birth Imbalances in the Future My demographic projections for China and India will start from 2005 and extend to 2100.They are based on the most recent demographic estimates as well as on assumptions that are different from previous attempts.Parameters for these projections have mostly been borrowed from the 2006 prospects by the United Nations Population Division,but several adjustments and corrections have been made (see Appendix A). SRB levels for the future decades are also essential to my projections.SRB started to increase above normal values 20 years ago in China and India (for China, Data used in this section are based on United Nations estimates for 1950-2005 complemented by projection results for the period beyond 2005. According to my projections,the overall yearly decline in birth cohort size during the 2005-2100 period is 0.25%in China and 0.4%in India (rapid transition scenario). No projection exists for India.Forecasts of China's future sex imbalances (Attane 2006;Tuljapurkar et al.1995)are based on 1990 or 2000 census data and on fixed fertility and mortality assumptions. Estimates provided by Jiang et al.(2007)follow a more realistic demographic scenario.An alternative method based on nuptiality tables has also been proposed by Jiang (2011). ②Springercohorts stems also from long-term trends: the number of annual births tends to increase during the first phase of the demographic transition but decreases later after prolonged fertility decline. India’s case is probably emblematic of this situation because the number of births recorded a regular increment until 1990. For instance, the annual increase in the birth cohort size reached 1.5% during the 1970s. This means that there were, on average, 7.7% more prospective wives born during this decade than husbands born five years earlier (five years being the current age difference at marriage), and this imbalance affected the marriage market 20 years later.2 Incidentally, this disequilibrium in the past is often associated with the concomitant rise in dowry observed in India after independence (Mari Bhat and Halli 1999). But with decreases in fertility and further changes in age structures, the number of births started declining in the 1990s, and, according to my population projections, this reduction in the size of birth cohorts is expected to accelerate in the future. For instance, by 2025, an average birth cohort in a given year would be 7% larger than the cohort born five years later. Without any rise in the SRB, male adults would therefore become more numerous than their prospective brides. China presents an undoubtedly more complicated picture because of the irregular size of its birth cohorts since the 1950s. While the number of births has, on the whole, decreased since the 1980s, this decline is less rapid than in India and also is disturbed by the regular ups and downs that are a legacy of China’s volatile demographic past. Short-term fluctuations therefore have a marked effect on age and sex distributions in China and will directly influence the sex ratio of adults—a point highlighted by Goodkind (2006) and Rallu (2006). But the decline in the number of births will also be pronounced in China, especially during 2020–2035.3 As a result, the impact of skewed SRBs in China and India on adult sex ratios is likely to be compounded by future age-structural transformations. I therefore insert a separate projection set designed to assess the potential influences of changes in age structures on marriage imbalances. Birth Imbalances in the Future My demographic projections for China and India will start from 2005 and extend to 2100. They are based on the most recent demographic estimates as well as on assumptions that are different from previous attempts.4 Parameters for these projections have mostly been borrowed from the 2006 prospects by the United Nations Population Division, but several adjustments and corrections have been made (see Appendix A). SRB levels for the future decades are also essential to my projections. SRB started to increase above normal values 20 years ago in China and India (for China, 2 Data used in this section are based on United Nations estimates for 1950–2005 complemented by projection results for the period beyond 2005. 3 According to my projections, the overall yearly decline in birth cohort size during the 2005–2100 period is 0.25% in China and 0.4% in India (rapid transition scenario). 4 No projection exists for India. Forecasts of China’s future sex imbalances (Attané 2006; Tuljapurkar et al. 1995) are based on 1990 or 2000 census data and on fixed fertility and mortality assumptions. Estimates provided by Jiang et al. (2007) follow a more realistic demographic scenario. An alternative method based on nuptiality tables has also been proposed by Jiang (2011). Skewed Sex Ratios at Birth and Future Marriage Squeeze 79