Long-term impacts of land dispossession: To date, we lack precise estimates of the extent to which Indigenous peoples in parts of North America were dispossessed of their lands and forced to migrate by colonial settlers, as well as how the lands that they were moved into compare to their original lands. Farrell et al . constructed a new dataset within the boundaries of the current-day United States and found that Indigenous land density and spread in has been reduced by nearly 99% (see the Perspective by Fixico). The lands to which they were forcibly migrated are more vulnerable to climate change and contain fewer resources. Research and policy implications of these findings are discussed. —TSR

Significance: Early in the US COVID-19 epidemic, Americans spent substantially more time at home to reduce cases. Disentangling voluntary from policy-induced behavioral changes is critical for governments grappling with relaxing or renewing restrictions. We estimate the number of additional reported cases that would have been needed to elicit a voluntary behavioral response equivalent to the behavioral response to policy. A substantial share of the observed behavioral response was voluntary. Stay-at-home orders increased the time people spent at home by replacing voluntary actions that likely would have emerged as cases rose. Our analysis is an initial step in answering the critical policy question as to whether fast forwarding the response provides sufficient public health benefits to justify the mandates.

Significance: Economists have long argued, with recent acceptance from the science and policy community, that natural resources are capital assets. Pricing of natural capital has remained elusive, with the result that its value is often ignored, and expenditures on conservation are treated as costs rather than investments. This neglect stems from a lack of a valuation framework to enable apples to apples comparisons with traditional forms of capital. We develop such an approach and demonstrate it on Kansas’ groundwater stock. Between 1996 and 2005, groundwater withdrawal reduced Kansas’ wealth approximately $110 million per year. Wealth lost through groundwater depletion in Kansas is large, but in a range where offsetting investments may be feasible.

Background: Violence is a leading cause of death and an important public health threat, particularly among adolescents and young adults. However, the environmental causes of violent behavior are not well understood. Emerging evidence suggests exposure to air pollution may be associated with aggressive or impulsive reactions in people. Methods: We applied a two-stage hierarchical time-series model to estimate change in risk of violent and nonviolent criminal behavior associated with short-term air pollution in U.S. counties (2000–2013). We used daily monitoring data for ozone and fine particulate matter (PM_2.5) from the Environmental Protection Agency and daily crime counts from the Federal Bureau of Investigation. We evaluated the exposure–response relation and assessed differences in risk by community characteristics of poverty, urbanicity, race, and age. Results: Our analysis spans 301 counties in 34 states, representing 86.1 million people and 721,674 days. Each 10 µg/m³ change in daily PM_2.5 was associated with a 1.17% (95% confidence interval [CI] = 0.90, 1.43) and a 10 ppb change in ozone with a 0.59% (95% CI = 0.41, 0.78) relative risk increase (RRI) for violent crime. However, we observed no risk increase for nonviolent property crime due to PM_2.5 (RRI: 0.11%; 95% CI = −0.09, 0.31) or ozone (RRI: −0.05%; 95% CI = −0.22, 0.12). Our results were robust across all community types, except rural regions. Exposure–response curves indicated increased violent crime risk at concentrations below regulatory standards. Conclusions: Our results suggest that short-term changes in ambient air pollution may be associated with a greater risk of violent behavior, regardless of community type.

Managing infectious disease is among the foremost challenges for public health policy. Interpersonal contacts play a critical role in infectious disease transmission, and recent advances in epidemi...