A multistate model of fecundability and sterility
Wood, J.W.; Holman, D.J.; Yashin, A.I.; Peterson, R.J.; Weinstein, M.; Chang, M.C.
Demography 31(3): 403-426
1994
ISSN/ISBN: 0070-3370 PMID: 7828764 DOI: 10.2307/2061750Document Number: 288140
This paper develops a multistate hazards model for estimating fecundability and sterility from data on waiting times to conception. Important features of the model include separate sterile and nonsterile states, a distinction between preexisting sterility and sterility that begins after initiation of exposure, and log-normally distributed fecundability among nonsterile couples. Application of the model to data on first birth intervals from Taiwan, Sri Lanka, and the Amish shows that heterogeneity in fecundability is statistically significant at most ages, but that preexisting sterility and new sterility are unimportant before age 40. These results suggest that sterility may not be an important determinant of natural fertility until later reproductive ages.