title: The third birth in Sweden.
abstract: "This paper considers the formulation, estimation and interpretation of microdynamic models of fertility.  Our model explains parity choices, sterility, childlessness, interbirth intervals and initiation of pregnancy within a unified framework.  We develop a general methodology for estimating the determinants of transition times to births of different orders. Our procedure incorporates time-varying explanatory variables and unobservables.  We present conditions that justify conventional formulae relating hazards to survivor functions when time-varying variables enter hazards.  We also consider the validity of widely-used piecemeal estimation strategies that focus on one birth at a time.  We consider methods for selecting a best model among a class of non-nested models.  Two criteria are set forth and used to evaluate the determinants of third births in Sweden."
authors.forename: J J
authors.initials: JJ
authors.lastname: Heckman
authors.forename: J R
authors.initials: JR
authors.lastname: Walker
mesh_terms: D001722:Birth Order; D001723:Birth Rate; D003710:Demography; D019049:Developed Countries; D005060:Europe; D005069:Evaluation Studies as Topic; D005191:Family Characteristics; D005195:Family Relations; D005298:Fertility; D011153:Population; D011157:Population Dynamics; D012106:Research; D012537:Scandinavian and Nordic Countries; D012725:Sexual Behavior; D013223:Statistics as Topic; D013548:Sweden
keywords: Birth Order; Demographic Factors; Developed Countries; Estimation Technics; Europe; Evaluation; Evaluation Methodology; Family And Household; Family Characteristics; Family Relationships; Fertility; Fertility Measurements; Northern Europe; Population; Population Dynamics; Reproductive Behavior; Research Methodology; Scandinavia; Sweden