In many developing countries, the average firm is small, does not grow, and has low productivity. Lack of market integration and limited information on non-local products often leave consumers unaware of the prices and quality of non-local firms. They therefore mostly buy locally, limiting firms’ potential market size (and competition). We explore this hypothesis using a natural experiment in the Kerala boat-building industry. As consumers learn more about non-local builders, high-quality builders gain market share and grow, while low-quality firms exit. Aggregate quality increases, as does labor specialization, and average production costs decrease. Finally, quality-adjusted consumer prices decline. (JEL D22, D83, L15, L25, L62, O12, O14)

Many developing countries use food-price subsidies or controls to improve nutrition. However, subsidizing goods on which households spend a high proportion of their budget can create large wealth effects. Consumers may then substitute towards foods with higher non-nutritional attributes (e.g., taste), but lower nutritional content per unit of currency, weakening or perhaps even reversing the subsidy's intended impact. We analyze data from a randomized program of large price subsidies for poor households in two provinces of China and find no evidence that the subsidies improved nutrition. In fact, it may have had a negative impact for some households. (JEL I38; O12; Q18).

This paper provides the first real-world evidence of Giffen behavior, i.e., upward sloping demand. Subsidizing the prices of dietary staples for extremely poor households in two provinces of China, we find strong evidence of Giffen behavior for rice in Hunan, and weaker evidence for wheat in Gansu. The data provide new insight into the consumption behavior of the poor, who act as though maximizing utility subject to subsistence concerns. We find that their elasticity of demand depends significantly, and nonlinearly, on the severity of their poverty. Understanding this heterogeneity is important for the effective design of welfare programs for the poor. (JEL D12, O12).

Social Security Disability Insurance (DI) awards rise in recessions, especially for workers over age 50. We use Medicare data to investigate how health, entry costs, and age-based DI eligibility rules shape this pattern. Entrants induced by recessions have lower medical spending and mortality than typical recipients. Entry responses to unemployment jump two- to fourfold at ages 50 and 55, when eligibility rules relax. Using these age-based discontinuities as instruments, we find no shift in marginal entrants' health across unemployment levels. These findings show that DI's age-based eligibility rules are a primary driver of cyclical entry, while health shocks are not.

The Effects of Environmental Regulation on Technology Diffusion: The Case of Chlorine Manufacturing by Lori D. Snyder, Nolan H. Miller and Robert N. Stavins. Published in volume 93, issue 2, pages 431-435 of American Economic Review, May 2003

We estimate how the mortality effects of temperature vary across U.S. climate regions to assess local and national damages from projected climate change. Using 22 years of Medicare data, we find that both cold and hot days increase mortality. However, hot days are less deadly in warm places while cold days are less deadly in cool places. Incorporating this heterogeneity into end-of-century climate change assessments reverses the conventional wisdom on climate damage incidence: cold places bear more, not less, of the mortality burden. Allowing places to adapt to their future climate substantially reduces the estimated mortality effects of climate change.

We estimate the causal effects of acute fine particulate matter exposure on mortality, health care use, and medical costs among the US elderly using Medicare data. We instrument for air pollution using changes in local wind direction and develop a new approach that uses machine learning to estimate the life-years lost due to pollution exposure. Finally, we characterize treatment effect heterogeneity using both life expectancy and generic machine learning inference. Both approaches find that mortality effects are concentrated in about 25 percent of the elderly population.