Fisher et al. (2012)––henceforth, FHRS––have uncovered coding and data errors in our paper, Deschênes and Greenstone (2007), henceforth, DG. We acknowledge and are embarrassed by these mistakes. We are grateful to FHRS for uncovering them. We hope that this Reply will also contribute to advancing the literature on the vital question of the impact of climate change on the US agricultural sector.

This paper measures the economic impact of climate change on US agricultural land by estimating the effect of random year-to-year variation in temperature and precipitation on agricultural profits. The preferred estimates indicate that climate change will increase annual profits by $1.3 billion in 2002 dollars (2002$) or 4 percent. This estimate is robust to numerous specification checks and relatively precise, so large negative or positive effects are unlikely. We also find the hedonic approach—which is the standard in the previous literature—to be unreliable because it produces estimates that are extremely sensitive to seemingly minor choices about control variables, sample, and weighting.

In many regulated markets, private, third-party auditors are chosen and paid by the firms that they audit, potentially creating a conflict of interest. This article reports on a two-year field experiment in the Indian state of Gujarat that sought to curb such a conflict by altering the market structure for environmental audits of industrial plants to incentivize accurate reporting. There are three main results. First, the status quo system was largely corrupted, with auditors systematically reporting plant emissions just below the standard, although true emissions were typically higher. Second, the treatment caused auditors to report more truthfully and very significantly lowered the fraction of plants that were falsely reported as compliant with pollution standards. Third, treatment plants, in turn, reduced their pollution emissions. The results suggest reformed incentives for third-party auditors can improve their reporting and make regulation more effective.

There is a growing consensus that emissions of greenhouse gases due to human activity will alter the earth’s climate, most notably by causing temperatures, precipitation levels, and weather variability to increase. The design of optimal climate change mitigation policies requires estimates of the health and other benefits of reductions in greenhouse gases; current evidence on the magnitude of the direct and indirect impacts, however, is considered insufficient for reliable conclusions (A. J. McMichael et al. 2003).

High pollution persists in many developing countries despite strict environmental rules. We use a field experiment and a structural model to study how plant emission standards are enforced. In collaboration with an Indian environmental regulator, we experimentally doubled the rate of inspection for treatment plants and required that the extra inspections be assigned randomly. We find that treatment plants only slightly increased compliance. We hypothesize that this weak effect is due to poor targeting, since the random inspections in the treatment found fewer extreme violators than the regulator's own discretionary inspections. To unbundle the roles of extra inspections and the removal of discretion over what plants to target, we set out a model of environmental regulation where the regulator targets inspections, based on a signal of pollution, to maximize plant abatement. Using the experiment to identify key parameters of the model, we find that the regulator aggressively targets its discretionary inspections, to the degree that half of the plants receive fewer than one inspection per year, while plants expected to be the dirtiest may receive ten. Counterfactual simulations show that discretion in targeting helps enforcement: inspections that the regulator assigns cause three times more abatement than would the same number of randomly assigned inspections. Nonetheless, we find that the regulator's information on plant pollution is poor, and improvements in monitoring would reduce emissions.

We study differences in quality in the market for third-party environmental auditors in Gujarat, India. We find that, despite the low overall quality, auditors are heterogeneous and some perform well. We posit that these high-quality auditors survive by using their good name to insulate select client plants from regulatory scrutiny. We find two pieces of evidence broadly consistent with this hypothesis: (i) though estimates are not precise, higher-quality auditors appear to be paid more both in their work as third-party auditors and in their complementary work as consultants; and (ii) plants with high-quality auditors incur fewer costly penalties from the regulator.

We are the first to examine the effect of Superfund cleanups on infant health rather than focusing on proximity to a site. We study singleton births to mothers residing within 5km of a Superfund site between 1989-2003 in five large states. Our "difference in differences" approach compares birth outcomes before and after a site clean-up for mothers who live within 2,000 meters of the site and those who live between 2,000- 5,000 meters of a site. We find that proximity to a Superfund site before cleanup is associated with a 20 to 25% increase in the risk of congenital anomalies.

The demand for air quality depends on health impacts and defensive investments, but little research assesses the empirical importance of defenses. A rich quasi-experiment suggests that the Nitrogen Oxides (NO x ) Budget Program (NBP), a cap-and-trade market, decreased NO x emissions, ambient ozone concentrations, pharmaceutical expenditures, and mortality rates. The annual reductions in pharmaceutical purchases, a key defensive investment, and mortality are valued at about $800 million and $1.3 billion, respectively, suggesting that defenses are over one-third of willingness-to-pay for reductions in NO x emissions. Further, estimates indicate that the NBP's benefits easily exceed its costs and that NO x reductions have substantial benefits.

Regulatory oversight of toxic emissions from industrial plants and understanding about these emissions' impacts are in their infancy. Applying a research design based on the openings and closings of 1,600 industrial plants to rich data on housing markets and infant health, we find that: toxic air emissions affect air quality only within 1 mile of the plant; plant openings lead to 11 percent declines in housing values within 0.5 mile or a loss of about $4.25 million for these households; and a plant's operation is associated with a roughly 3 percent increase in the probability of low birthweight within 1 mile.

This paper assesses the role of heating entitlements in generating stark air quality differences across China. During the 1950-1980 central planning period, the Chinese government established free winter heating of homes and offices as a basic right via the provision of free coal fuel for boilers. The combustion of coal in boilers is associated with the release of air pollutants, especially total suspended particulates (TSP). Due to budgetary limitations, however, this heating entitlement was only extended to areas to the north of the line formed by the Huai River and Qinling Mountains in central China. We find this procrustean policy led to dramatically higher TSP levels in the north; the difference is roughly 5-8 times current TSP concentrations in the US. This result holds both in a cross-sectional regression discontinuity-style estimation approach and in a panel data setting that compares the marginal effect of winter temperature on TSP in northern and southern China. In contrast, we fail to find evidence that the heating policy has a meaningful impact on sulfur dioxide (SO2) and nitrogen oxide (NOx) concentrations.