This paper measures the economic impact of climate change on US agricultural land. We replicate the previous literature's implementation of the hedonic approach and find that it produces estimates of the effect of climate change that are very sensitive to decisions about the appropriate control variables, sample and weighting. We find estimates of the benchmark doubling of greenhouse gases on agricultural land values that range from a decline of $420 billion (1997$) to an increase of $265 billion, or -30% to 19%. Despite its theoretical appeal, the wide variability of these estimates suggests that the hedonic method may be unreliable in this setting. In light of the potential importance of climate change, this paper proposes a new strategy to determine its economic impact. We estimate the effect of weather on farm profits, conditional on county and state by year fixed effects, so the weather parameters are identified from the presumably random variation in weather across counties within states. The results suggest that the benchmark change in climate would reduce the value of agricultural land by $40 to $80 billion, or -3% to -6%, but the null of zero effect cannot be rejected. In contrast to the hedonic approach, these results are robust to changes in specification. Since farmers can engage in a more extensive set of adaptations in response to permanent climate changes, this estimate is likely downwards biased, relative to the preferred long run effect. Together the point estimates and sign of the likely bias contradict the popular view that climate change will have substantial negative welfare consequences for the US agricultural sector.

This paper measures the economic impact of climate change on US agricultural land by estimating the effect of the presumably random year-to-year variation in temperature and precipitation on agricultural profits. Using long-run climate change predictions from the Hadley 2 Model, the preferred estimates indicate that climate change will lead to a $1.3 billion (2002$) or 4.0% increase in annual profits. The 95% confidence interval ranges from -$0.5 billion to $3.1 billion and the impact is robust to a wide variety of specification checks, so large negative or positive effects are unlikely. There is considerable heterogeneity in the effect across the country with California’s predicted impact equal to -$0.75 billion (or nearly 15% of state agricultural profits). Further, the analysis indicates that the predicted increases in temperature and precipitation will have virtually no effect on yields among the most important crops, which suggest that the small effect on profits are not due to short-run price increases. The paper also implements the hedonic approach that is predominant in the previous literature and finds that it may be unreliable, because it produces estimates of the effect of climate change that are extremely sensitive to seemingly minor decisions about the appropriate control variables, sample and weighting. Overall, the findings contradict the popular view that climate change will have substantial negative welfare consequences for the US agricultural sector.

This paper produces the first large-scale estimates of the US health related welfare costs due to climate change. Using the presumably random year-to-year variation in temperature and two state of the art climate models, the analysis suggests that under a ‘business as usual’ scenario climate change will lead to an increase in the overall US annual mortality rate ranging from 0.5% to 1.7% by the end of the 21st century. These overall estimates are statistically indistinguishable from zero, although there is evidence of statistically significant increases in mortality rates for some subpopulations, particularly infants. As the canonical Becker-Grossman health production function model highlights, the full welfare impact will be reflected in health outcomes and increased consumption of goods that preserve individuals’ health. Individuals’ likely first compensatory response is increased use of air conditioning; the analysis indicates that climate change would increase US annual residential energy consumption by a statistically significant 15% to 30% ($15 to $35 billion in 2006 dollars) at the end of the century. It seems reasonable to assume that the mortality impacts would be larger without the increased energy consumption. Further, the estimated mortality and energy impacts likely overstate the long-run impacts on these outcomes, since individuals can engage in a wider set of adaptations in the longer run to mitigate costs. Overall, the analysis suggests that the health related welfare costs of higher temperatures due to climate change are likely to be quite modest in the US.

The 1964 Securities Acts Amendments extended the mandatory disclosure requirements that had applied to listed firms since 1934 to large firms traded Over-the-Counter (OTC). We find several pieces of evidence indicating that investors valued these disclosure requirements, two of which are particularly striking. First, a firm-level event study reveals that the OTC firms most affected by the 1964 Amendments had abnormal excess returns of about 3.5 percent in the weeks immediately surrounding the announcement that they had begun to comply with the new requirements. Second, we estimate that the most affected OTC firms had abnormal excess returns ranging between 11.5 and 22.1 percent in the period between when the legislation was initially proposed and when it went into force. These returns are adjusted for the standard four factors and are relative to NYSE/AMEX firms, matched on size and book-to-market equity, that were unaffected by the legislation. While we cannot determine how much of shareholders' gains were a transfer from insiders of these same companies, our results suggest that mandatory disclosure causes managers to focus more narrowly on maximizing shareholder value.