Knowledge that Transforms

When credit markets to finance investment in human capital are missing, the competitive equilibrium allocation is inefficient. When generations overlap, this failure can be mitigated by properly designed social arrangements. We show that public financing of education and public pensions can be designed to implement an intergenerational transfer scheme supporting the complete market allocation. Neither the public financing of education nor the pension scheme we consider resemble standard ones. In our mechanism, via the public education system, the young borrow from the middle aged to invest in human capital. They pay back the debt via a social security tax, the proceedings of which finance pension payments. When the complete market allocation is achieved, the rate of return implicit in this borrowing-lending scheme should equal the market rate of return.

We characterize infrequent durables stock adjustment by consumers who also derive utility from non-durable consumption flows in the presence of idiosyncratic income uncertainty. The data we analyse include subjective future income uncertainty measures, which we use as instruments in the estimation of relevant parameters of heterogeneous consumers' dynamic adjustment problems. The data feature two conceptually distinct sources of variation: cross-sectional heterogeneity of the sampled households' dynamic problems, and history-dependent heterogeneity in their situation during the observation period. We note that the latter should affect the likelihood but not the size of stock adjustment decisions, and find broad support for theoretical predictions in formal selection-controlled regressions based on this insight.

Many people assume that the most significant risk in the housing market is that homeowners are exposed to fluctuations in house values. However, homeownership also provides a hedge against fluctuations in future rent payments. This paper finds that, even though house price risk endogenously increases with rent risk, the latter empirically dominates for most households -so housing market risk actually increases homeownership rates and house prices.

We measure media bias by estimating ideological scores for several major media outlets. To compute this, we count the times that a particular media outlet cites various think tanks and policy groups, then compare this with the times that members of Congress cite the same groups. Our results show a strong liberal bias: all of the news outlets we examine, except Fox News ’ Special Report and the Washington Times, received scores to the left of the average member of Congress. Consistent with claims made by conservative critics, CBS Evening News and the New York Times received scores far to the left of center. The most centrist media outlets were PBS NewsHour, CNN’s Newsnight, and ABC’s Good Morning America; among print outlets, USAToday was closest to the center. All of our findings refer strictly to news content; that is, we exclude editorials, letters, and the like.

This paper formalizes a widely discussed peer effect titled “acting White.” “Acting White” is modeled as a two-audience signaling quandary: signals that induce high wages can be signals that induce peer group rejection. Without peer effects, equilibria involve all ability types choosing different levels of education. “Acting White” alters the equilibrium dramatically: the (possibly empty) set of lowest ability individuals and the set of highest ability individuals continue to reveal their type through investments in education; ability types in the middle interval pool on a common education level. Only those in the lower intervals are accepted by the group. The model's predictions fit many stylized facts in the anthropology and sociology literatures regarding social interactions among minority group members.

Birth weight has emerged as the leading indicator of infant health and welfare and the central focus of infant health policy. This is because low birth weight (LBW) infants experience severe health and developmental difficulties that can impose enormous costs on society. But would the prevention of LBW generate equally sizable cost savings and health improvements? Estimates of the return to LBW-prevention from cross-sectional associations may be biased by omitted variables that cannot be influenced by policy, such as genetic factors. To address this, we compare the hospital costs, health at birth, and infant mortality rates between heavier and lighter infants from all twin pairs born in the United States. We also examine the effect of maternal smoking during pregnancy n the leading risk factor for LBW in the United States n on health among singleton births after controlling for detailed background characteristics. Both analyses imply substantially smaller effects of LBW than previously thought, suggesting two possibilities: 1) existing estimates overstate the true costs and consequences of LBW by at least a factor of four and by as much as a factor of 20;

Forty million people are infected with HIV worldwide; twenty-five million of them are in Sub-Saharan Africa. This paper addresses the question of why Africa has been so heavily affected by HIV, and what explains the variation within Africa. I present a model that decomposes epidemic level into differences in sexual behavior and differences in viral transmission rates. I argue, using evidence drawn from the existing medical literature, that Africa has very high HIV transmission rates, likely due to high rates of other untreated sexually transmitted infections, while transmission rates in the United States are low. The difference in transmission rates is large enough to explain the observed difference in prevalence between the United States and Sub-Saharan Africa. The model also provides a good fit to cross-country data within Africa and suggests that, in contrast to the intra-continental results, differences within that continent can be attributed to differences in sexual behavior and epidemic timing. The results suggest that cost-effective policy interventions would focus on decreasing transmission rates within Africa, possibly by treating other untreated sexually transmitted infections.

Among 188 countries, 72 had no state religion in 2000,1970, and 1900; 58 had a state religion throughout; and 58 had 1 or 2 transitions. We use a Hotelling spatial competition model to analyze the likelihood that the religion market would be monopolized. Similar forces influence a government's decision to establish a state religion. Consistent with the model, the probability of state religion in 1970 and 2000 is increasing with the adherence rate to the main religion, has a nonlinear relation with population, and has little relation with per capita GDP. The probability of state religion decreases sharply under Communism, but lagged Communism has only a weak effect. With costly adjustment for institutions, the probability of state religion in 1970 or 2000 depends substantially on the status in 1900. This persistence is much stronger for countries with no major regime change than for countries with such a change.

We present an argument for changes in the franchise in which an elite split along economic interests uses the suffrage to influence implemented policies. Through the influence of these policies on the character of industrialization, we analyze the effects of franchise changes on economic growth. We identify in the social structure of society an explanation for the connection between enfranchisement and growth: when (1) there exists an economic conflict among the elite, (2) landed classes are not politically strong, and (3) there exists a critical mass of industrial workers, we observe both growth and democratization. The lack of conditions (1) or (2) resolves in stagnant autocracies while the absence of condition (3) drives growth-deterring democratic expansions. We provide historical support for our argument by analyzing the experience of eleven countries.

We show the importance of a dynamic aggregation bias in accounting for the PPP puzzle. We prove that the aggregate real exchange rate is persistent because its components have heterogeneous dynamics. Established time series and panel methods fail to control for this. Using Eurostat data, we find that when heterogeneity is taken into account, the estimated persistence of real exchange rates falls dramatically. Its half-life, for instance, may fall to as low as eleven months, significantly below the “consensus view” of three to five years.