Income composition, endogenous fertility and schooling investments in children

This paper studies how the eomposition of ineome between mothers and fathers affeets fertility and sehooling investments in ehildren, using data from the 1976 and 1996 PNAD, a Brazilian household survey. Ineome composition affeets the time eost of fertility because mothers and fathers alloeate different amounts of time to child-rearing. These effects are in turn transmitted to investments in ehildren through a tradeoffbetween quantity and quality of ehildren. The main contribution of this paper is twofold. First, it derives new implications about the relationship between household ineome composition and schooling investments in ehildren. Seeond, this paper devises and implements an empirieal approaeh to assess these implieations, using two eross-seetions of fertility and schooling data from Brazil. The main empirical findings of the paper ean be summarized as follows. First, the empirical analysis shows that a larger negative effect of the mother's labor in come on fertility in 1996 is associated with a larger positive effect on the adult child's schooling, refleeting the interaction between quantity and quality of children. Second, the larger negative effect of the mother's labor income on fertility in 1996 is associated with a reduction in the effect of other determinants of number of children. This suggests that an increase in the relative importanee of time costs of fertility may be an important determinant of variations in fertility over time in Brazil and other developing countries .

A competitive growth model with endogenous fertility

This paper investigates the interaction between endogenous fertility behavior and the distribution of income and wealth arnong farnilies in a competitive market economy. We construct a growth model in which altruistic dynasties are heterogeneous in their initial stocks of physical capital. Dynasties make choices of farnily size along with decisions about consumption and intergenerational transfers. We show that if the rate of time preference is increasing in the number of children and preferences over nurnber of children satisfy a norrnality assumption, all steady states are characterized by equality of capital stocks and consumption arnong families. We also provide sufficient conditions for uniqueness of the steady state. In order to illustrate these results, we present an example in which preferences over number of children are logarithrnic and the technology is Cobb-Douglas. For this combination of preferences and technology, there exists a unique egalitarian steady state. Moreover, the economy converges to this steady state in only one generation .

Wealth composition, endogenous fertility and the dynamics of income inequality

This paper analyzes how differences in the composition of wealth between human and physical capital among families affect fertility choices. These in tum influence the dynamics of wealth and income inequality across generations through a tradeoffbetween quantity and quality of children. Wealth composition affects fertility because physical capital has only a wealth effect on number of children, whereas human capital increases the time cost of child-rearing in addition to the wealth effect. I construct a model combining endogenous fertility with borrowing constraints in human capital investments, in which weaIth composition is determined endogenously. The model is calibrated to the PNAD, a Brazilian household survey, and the main findings of the paper can be summarized as follows. First, the model implies that the crosssection relationship between fertility and wealth typically displays a U-shaped pattem, reflecting differences in wealth composition between poor and rich families. Also, the quantity-quality tradeoff implies a concave cross-section relationship between investments per child and wealth. Second, as the economy develops and families overcome their bOlTowing constraints, the negative effect of weaIth on fertility becomes smaller, and persistence of inequality declines accordingly. The empirical evidence presented in this paper is consistent with both implications .

Optimal debt, endogenous fertility, and human capital externalities in a model with altruistic bequests

and human capital externalities. Because of such externalities, education investment is too low and fertility is too high. While education subsidies are the conventional means to deal with these problems, we show that the optimal policy also comprises debt even when distortionary taxes are used. The reason is that debt tips the usual trade-off between children's quantity and quality in favor of the latter by increasing the bequest cost of children. The optimal debt-output ratio exceeds 10% for plausible parameterization. (C) 2002 Elsevier B.V. All rights reserved.

Fertility choice, land, and the Malthusian hypothesis

In a standard overlapping generations growth model, with a fixed amount of land and endogenous fertility, the competitive economy converges to a steady state with a zero population growth rate and positive consumption per capita. The Malthusian hypothesis is interpreted as a positive statement about the relationship between population growth and consumption per-capita, when production exhibits diminishing returns to labor and there is a fixed amount of land essential for production. Even when individuals care only about the number of their children and not about their children's welfare, the equilibrium is such that they eventually would choose to have only one child for each adult. Hence, if Malthus's "positive check' on population is the result of the response of optimizing agents to competitively determined prices, Malthus's pessimistic conjecture is not necessarily true, even though his other assumptions hold. -from Authors

Second-best public debt with human capital externalities

This paper studies optinnal public debt in a dynastic model with human capital externalities that cause human capital investment (fertility) to be below (above) its socially optimal level. By reducing fertility and raising human capital investment, the optimal debt can exceed 10% of output for plausible parameterizations.

A Need for FSH in Maintaining Fertility of Adult Male Subhuman Primates

Adult fertile male bonnet monkeys (Macaca radiata) were continuously deprived of endogenous follicle stimulating hormone (FSH) support for 240 days by injecting them with 1 ml of characterized monkey antiserum to oFSH every 48 hr; control monkeys received during the same period normal monkey serum instead. Testicular function was assessed at periodic intervals by (a) carrying out differential counting of sperm in the ejaculate obtained and (b) determining the hyaluronidase activity as well as in vitro 3H thymidine incorporation into DNA of testicular tissue removed at biopsy. Both the quality (viability and motility) of the sperms voided and the total sperm counts showed marked decreases as a function of time of immunization, the first significant reduction being noted by 100 days. FSH deprivation affected both the biochemical parameters used to test testicular functionality they being reduced at ∼200 days by 50%-60%. The fertility of these monkeys was evaluated at periodic times after 90 days of treatment by means of mating studies. FSH deprivation had rendered the monkeys incapable of impregnating any of the females used. Testosterone and luteinizing hormone (LH) levels remained unchanged following FSH antiserum injection. With cessation of antiserum treatment testicular function and fertility were completely restored to normalcy, indicating that the observed effect was specifically due to FSH deprivation. This study thus provides conclusive evidence for the involvement of FSH in maintenance of testicular function and fertility in the adult male primate.

Auxin-Responsive OsMGH3, a Common Downstream Target of OsMADS1 and OsMADS6, Controls Rice Floret Fertility

GH3 proteins control auxin homeostasis by inactivating excess auxin as conjugates of amino acids and sugars and thereby controlling cellular bioactive auxin. Since auxin regulates many aspects of plant growth and development, regulated expression of these genes offers a mechanism to control various developmental processes. OsMGH3/OsGH3-8 is expressed abundantly in rice florets and is regulated by two related and redundant transcription factors, OsMADS1 and OsMADS6, but its contribution to flower development is not known. We functionally characterize OsMGH3 by overexpression and knock-down analysis and show a partial overlap in these phenotypes with that of mutants in OsMADS1 and OsMADS6. The overexpression of OsMGH3 during the vegetative phase affects the overall plant architecture, whereas its inflorescence-specific overexpression creates short panicles with reduced branching, resembling in part the effects of OsMADS1 overexpression. In contrast, the down-regulation of endogenous OsMGH3 caused phenotypes consistent with auxin overproduction or activated signaling, such as ectopic rooting from aerial nodes. Florets in OsMGH3 knock-down plants were affected in carpel development and pollen viability, both of which reduced fertility. Some of these floret phenotypes are similar to osmads6 mutants. Taken together, we provide evidence for the functional significance of auxin homeostasis and its transcriptional regulation during rice panicle branching and floret organ development.

Fertility and the value of Life

The value of life methodology has been recently applied to a wide range of contexts as a means to evaluate welfare gains attributable to mortality reductions and health improvements. Yet, it suffers from an important methodological drawback: it does not incorporate into the analysis child mortality, individuals’ decisions regarding fertility, and their altruism towards offspring. Two interrelated dimensions of fertility choice are potentially essential in evaluating life expectancy and health related gains. First, child mortality rates can be very important in determining welfare in a context where individuals choose the number of children they have. Second, if altruism motivates fertility, life expectancy gains at any point in life have a twofold effect: they directly increase utility via increased survival probabilities, and they increase utility via increased welfare of the offspring. We develop a manageable way to deal with value of life valuations when fertility choices are endogenous and individuals are altruistic towards their offspring. We use the methodology developed in the paper to value the reductions in mortality rates experienced by the US between 1965 and 1995. The calculations show that, with a very conservative set of parameters, altruism and fertility can easily double the value of mortality reductions for a young adult, when compared to results obtained using the traditional value of life methodology.

Slimmer or Fertile? Pharmacological Mechanisms Involved in Reduced Sperm Quality and Fertility in Rats Exposed to the Anorexigen Sibutramine

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The effect of life expectancy on fertility, saving, schooling and economic growth: theory and evidence

We construct a simple growth model where agents with uncertain survival choose schooling time, life-cycle consumption and the number of children. We show that rising longevity reduces fertility but raises saving, schooling time and the growth rate at a diminishing rate. Cross-section analyses using data from 76 countries support these propositions: life expectancy has a significant positive effect on the saving rate, secondary school enrollment and growth but a significant negative effect on fertility. Through sensitivity analyses, the effect on the saving rate is inconclusive, while the effects on the other variables are robust and consistent. These estimated effects are decreasing in life expectancy. Copyright The editors of the Scandinavian Journal of Economics 2005.

Health, endogenous time preference, and inequality : a political economy perspective

We study an overlapping-generations model in which agents' mortality risks, and consequently impatience, are endogenously determined by private and public investment in health care. Revenues allocated for public health care arc determined by a voting process. We find that the degree of substitutability between public and private health expenditures matters for macroeconomic outcomes of the model. Higher substitutability implies a “crowding-out" effect, which in turn impacts adversely on morality risks and impatience leading to lower public expenditures on health care in the political equilibrium. Consequently, higher substitutability is associated with greater polarization in wealth, and long-run distributions that are bimodal.