Knowledge that Transforms

We examine long-term neighborhood effects on low-income families using data from the Moving to Opportunity (MTO) randomized housing-mobility experiment. This experiment offered to some public-housing families but not to others the chance to move to less-disadvantaged neighborhoods. We show that ten to 15 years after baseline, MTO: (i) improves adult physical and mental health; (ii) has no detectable effect on economic outcomes or youth schooling or physical health; and (iii) has mixed results by gender on other youth outcomes, with girls doing better on some measures and boys doing worse. Despite the somewhat mixed pattern of impacts on traditional behavioral outcomes, MTO moves substantially improve adult subjective well-being.

Cross-country labor productivity differences are larger in agriculture than in non-agriculture. We propose a new explanation for these patterns in which the self-selection of heterogeneous workers determines sector productivity. We formalize our theory in a general-equilibrium Roy model in which preferences feature a subsistence food requirement. In the model, subsistence requirements induce workers that are relatively unproductive at agricultural work to nonetheless select into the agriculture sector in poor countries. When parameterized, the model predicts that productivity differences are roughly twice as large in agriculture as non-agriculture even when countries differ by an economy-wide efficiency term that affects both sectors uniformly.

We explain a counterintuitive empirical finding: Firms facing more import competition do more innovation. In our model, factors are trapped inside a firm. An increase in import competition encourages a firm to innovate by reducing the opportunity cost of inputs. Without trapped factors, trade liberalization leads to a small permanent increase in the worldwide rate of growth. With trapped factors, firms that face more import competition do relatively more innovation. The extra innovation induced by trapped factors induces a small permanent increase in aggregate output, consumption, and welfare, generalizing the appropriate estimate of the gains from trade.

This paper investigates consumer inertia in health insurance markets, where adverse selection is a potential concern. We leverage a major change to insurance provision that occurred at a large firm to identify substantial inertia, and develop and estimate a choice model that also quantifies risk preferences and ex ante health risk. We use these estimates to study the impact of policies that nudge consumers toward better decisions by reducing inertia. When aggregated, these improved individual-level choices substantially exacerbate adverse selection in our setting, leading to an overall reduction in welfare that doubles the existing welfare loss from adverse selection.

We extend the model of Fullerton, Karney, and Baylis (2012) to explore cost-effectiveness of unilateral climate policy in the presence of leakage. We ignore the welfare gain from reducing greenhouse gas emissions, and focus on the welfare cost of the emissions tax or permit scheme. Whereas that prior paper solves for changes in emissions quantities and finds that leakage may be negative, we show here that all cases with negative leakage in that model are cases where a unilateral carbon tax results in a welfare loss. With positive leakage, however, a unilateral policy can improve welfare.

This paper studies the effect of improved early life health care on mortality and long-run academic achievement in school. We use the idea that medical treatments often follow rules of thumb for assigning care to patients, such as the classification of Very Low Birth Weight (VLBW ), which assigns infants special care at a specific birth weight cutoff. Using detailed administrative data on schooling and birth records from Chile and Norway, we establish that children who receive extra medical care at birth have lower mortality rates and higher test scores and grades in school. These gains are in the order of 0.15–0.22 standard deviations.

We present a new framework to identify supply elasticities of storable commodities where past shocks are used as exogenous price shifters. In the agricultural context, past yield shocks change inventory levels and futures prices of agricultural commodities. We use our estimated elasticities to evaluate the impact of the 2009 Renewable Fuel Standard on commodity prices, quantities, and food consumers' surplus for the four basic staples: corn, rice, soybeans, and wheat. Prices increase 20 percent if one-third of commodities used to produce ethanol are recycled as feedstock, with a positively skewed 95 percent confidence interval that ranges from 14 to 35 percent.

Preliminary findings are presented from a research project which examined the interactions between informal risk sharing, index insurance and risk-taking. Rainfall insurance contracts were randomly offered to cultivating and landless households in a set of Indian villages where preexisting census data on caste networks allowed the characterization of the nature and extent of informal risk sharing. We study how informal risk sharing mediates the demand for index insurance, whether index insurance or informal indemnification allows farmers to invest in risky technologies, and the general equilibrium effects of offering insurance contracts to cultivators and agricultural laborers.

I explore the association between regional variations in physician behavior and the geographical scope of malpractice standards of care. I estimate a 30–50 percent reduction in the gap between state and national utilization rates of various treatments and diagnostic procedures following the adoption of a rule requiring physicians to follow national, as opposed to local, standards. These findings suggest that standardization in malpractice law may lead to greater standardization in practices and, more generally, that physicians may indeed adhere to specific liability standards. In connection with the estimated convergence in practices, I observe no associated changes in patient health.

We analyze the emergence of the first socioeconomic institution in history limiting fertility: west of a line from St. Petersburg to Trieste, the European Marriage Pattern (EMP) reduced childbirths by approximately one-third between the fourteenth and eighteenth century. To explain the rise of EMP we build a two-sector model of agricultural production—grain and livestock. Women have a comparative advantage in animal husbandry. After the Black Death in 1348–1350, land abundance triggered a shift toward the pastoral sector. This improved female employment prospects, leading to later marriages. Using detailed data from England, we provide strong evidence for our mechanism.