This paper presents evidence from empirical studies that test hypotheses derived from models of household behavior pertaining to the interrelationships among population growth, human capital, and economic development. These studies have exploited quasi-natural experiments embodied in the cross-area variability in the wage rates of children in a number of low-income countries, the intercouple variation in the biological propensity to conceive, and the geographically selective introduction of new high-yielding seed varieties in India in the period 1961-71. The different varieties of evidence support the hypotheses that alterations in the returns to human capital associated with exogenous technical change lead simultaneously to increases in human capital investments and to reductions in fertility and that the costliness of fertility control is a significant but modest factor in inhibiting human capital investments.

A multiperiod household model of fertility behavior applicable to rural-agricultural settings in which the pecuniary as well as the psychic returns from children are significant is formulated. Implications regarding the effects of variables associated with the market for agricultural labor on the demand for farm children, including technical change, agricultural wage rates, farm value, and nonfarm employment opportunities, derived from the model are tested on U.S. aggregate data covering the period 1939-60. The empirical results obtained appear to support the theoretical model and suggest the importance of the reduction in the value of children as productive assets in agriculture as a factor in the postwar decline in the U.S. farm birth rate.

A significant proportion of migration in low-income countries, particularly in rural areas, is composed of moves by women for the purpose of marriage. We seek to explain these mobility patterns by examining marital arrangements among Indian households. In particular, we hypothesize that the marriage of daughters to locationally distant, dispersed yet kinship-related households is a manifestation of implicit interhousehold contractual arrangements aimed at mitigating income risks and facilitating consumption smoothing in an environment characterized by information costs and spatially covariant risks. Analysis of longitudinal South Indian village data lends support to the hypothesis. Marriage cum migration contributes significantly to a reduction in the variability of household food consumption. Farm households afflicted with more variable profits tend to engage in longer-distance marriage cum migration. The hypothesized and observed marriage cum migration patterns are in dissonance with standard models of marriage or migration that are concerned primarily with search costs and static income gains.

Household-level panel data from a nationally representative sample of rural Indian households describing the adoption and profitability of high-yielding seed varieties (HYVs) associated with the Green Revolution are used to test the implications of a model incorporating learning by doing and learning spillovers. The estimates indicate that (i) imperfect knowledge about the management of the new seeds was a significant barrier to adoption; (ii) this barrier diminished as farmer experience with the new technologies increased; (iii) own experience and neighbors' experience with HYVs significantly increased HYV profitability; and (iv) farmers do not fully incorporate the village returns to learning in making adoption decisions.

In this paper we formulate and estimate a finite-horizon, structural dynamic model of agricultural investment behavior that incorporates the major features of low-income agricultural environments: income uncertainty, constraints on borrowing and rental markets, and the use of investment assets to generate income and smooth consumption. The model is fit to longitudinal Indian household data on farm profits, bullock stocks, and pump sets. The estimated structural parameters are used to assess the effects on the life cycle accumulation of bullocks, agricultural profits, and welfare associated with complete markets and bullock liquidity and with second-best policies that provide assured sources of income to farmers and weather insurance.

The implications of the economic theories of marriage and of household fertility behavior are tested in a framework in which educational investment, marital search, and marital matches are responsive to marriage-market conditions and the personal traits of individual agents, some of which are unobserved by the econometrician. Implications are also derived and tested for the effects of longevity, attractiveness, preferences, and labor- and marriage-market conditions on schooling, marriage age, and spouse choice. The empirical results indicate that inattention to heterogeneity and martial selection leads to a false rejection of the economic theory of marriage but to a false acceptance of the value-of-time fertility hypothesis.

The household production literature emphasizes that technical or biological processes condition input selection by households in their production activities, along with prices and income. Exogenous variations in health, to the extent that they are perceived by individuals (heterogeneity), lead to correlations between inputs and health outcomes that cannot be used to derive causal conclusions. Therefore, estimates of health technology must be obtained from a behavioral model in which health inputs are themselves choices. Consistent estimates are reported of the effect of endogenous inputs, such as medical care, smoking, and fertility, on birth weight and fetal growth in the presence of health heterogeneity.

Although estimates of the fertility-labor supply relationship abound, a full appreciation of the interpretation of such estimates has been lacking, regardless of the empirical strategy employed. This paper attempts to elucidate, within the context of a life-cycle decision-making process, the information contained in the estimated association between fertility and labor supply as calculated from "single" and "simultaneous-equations" estimation techniques. We also present a statistical methodology based upon the occurrence of twins in the first pregnancy and provide estimates, using that methodology, of the extent to which women's life-cycle labor supply decisions respond to exogenous (and, in this case, unanticipated) extra children.

The roles of the entitlements of the AFDC program and marital prospects in the fertility and marriage choices of young women are assessed in the context of a model incorporating heritable endowment heterogeneity, assortative mating, concern for child quality, and potential parental and public support alternatives. Estimates based on data describing the fertility and marital experience up to age 23 of the eight birth cohorts of women in the NLSY provide evidence that higher AFDC benefit levels and lower marital prospects induce young women to choose to have a child outside of marriage.