This paper analyzes the effectiveness of a public agency’s managerial decision intended to promote biodiversity on the lands that it owns. The agency is the East Bay Municipal Utility District (EBMUD) that provides water to most of the eastern San Francisco Bay Area. In the 1940s, it planted non-native Monterey Pines on a 366 acre parcel by the San Pablo Reservoir referred to as the horse-logging area. Late in that century, it decided that the nonnative Monterey Pines were not consistent with its goal of promoting biodiversity on the lands that it stewards, and that these lands should be allowed to return gradually and naturally to their native oak woodland. By the turn of the century, many of the Monterey Pines were weak and dying. Starting in 2002, EBMUD allowed these lands to be regularly surveyed to assess the breeding bird population in them. This paper analyzes the survey data from 2002-2018 to consider how the bird population has changed and if the change is one that promotes biodiversity. The paper finds that biodiversity has increased significantly by multiple measures. The paper rejects two alternative hypotheses to explain the biodiversity increase: (1) that it could be part of a broader regional trend of avian biodiversity increase, and (2) that it could be an artifact of the survey methodology. EBMUD’s decision to allow these lands to return gradually to their native vegetation was effective; it has resulted in a significant increase in avian biodiversity. This increase includes the presence in 2010-2018 of important species that were not present in 2002-2009, including migratory species like the Olive-sided Flycatcher, Ash-throated Flycatcher, and Black-headed Grosbeak. More generally, the evidence in this study supports the idea that native vegetation promotes biodiversity.

We use novel, large-scale data on 43 million Americans from the 2000 Census and the 2001 to 2013 American Communities Survey linked to the Social Security Administration’s NUMIDENT to study how a policy-driven increase in economic resources for families affects children’s long-term outcomes. Using variation from the county-level roll-out of the Food Stamps program between 1961 and 1975, we find that children with access to greater economic resources before age five experience an increase of 6 percent of a standard deviation in their adult human capital, 3 percent of a standard deviation in their adult economic self-sufficiency, 8 percent of a standard deviation in the quality of their adult neighborhoods, 0.4 percentage-point increase in longevity, and a 0.5 percentage-point decrease in likelihood of being incarcerated. Based on these estimates, we conclude that Food Stamps’ transfer of resources to families is a highly cost-effective investment into young children, yielding a marginal value of public funds of approximately 56.

Contaminated sediments in rivers, lakes, and harbors around the world result in diminished ecological health, degradation of environmental resources, economic losses, and, in rare cases, impacts to human health. Despite the ongoing interest in the cleanup of contaminated sediments in rivers and harbors, little progress has been made in reducing the number of contaminated sites worldwide. Much of the difficulty in advancing this cause can be attributed to the high cost of sediment cleanups and the difficulty in assigning financial responsibility for the cost of the cleanup. Simple schemes dependent on identifying polluters are fraught with underlying complexity. More elaborate approaches tied in with waterfront redevelopment show some promise but are yet to be applied routinely. New advances in the understanding of how sediments may, or may not, factor into circularity pose new challenges and opportunities, with the potential to complement new funding paradigms. The most promising possibilities for achieving circularity in sediment management lie in a kind of “punctuated circularity,” which requires idiosyncratic, project-based beneficial use opportunities. However, these ideal situations are likely to remain rare for the foreseeable future, without advancements in technology and regulatory approaches, as well as development of market demand for the products made from contaminated sediments.

For most of US history, the federal government let states conduct congressional elections with only minimal interference. This changed with Congress’s passage of the Voting Rights Act (1964) and the Supreme Court’s one-man-one-vote (“OMOV”) decision in Carr (1965). Yet even then the Supreme Court stopped short of overruling gerrymandered congressional districts. Fifteen years ago, Justice Kennedy acknowledged that workable approaches still did not exist, but challenged litigants to do better. The Supreme Court’s devastating opinion in Rucho v. Common Cause (2019) marks the end of this experiment.The question remains whether some fresh departure can satisfy the Court’s objections.

This paper investigates the leading candidates. The most conservative possibility is to tighten traditional visual criteria like “contiguity” and “compactness” to make them binding. We present detailed numerical arguments showing that such rules would have to be so stringent as to deprive legislators of practically all discretion in drawing lines. This, however, would split communities at random. We argue that this (a) violates OMOV just as a deliberate gerrymander would, and (b) disrupts grassroots networks that voters rely on to educate themselves, making votes less valuable to those who cast them. It follows that OMOV is always improved by replacing random districting with determinate rules that track communities.

Our second candidate implements this strategy. Remarkably, recent social science research shows (a) that education and social pressure across voters play an important role in shaping community opinion, and (b) that the probability of such interactions between voters can be reliably estimated from an inverse square law. We describe a new open source software program that uses these insights to track community and test it against county-level population data from Texas. We show that the resulting maps are visually similar to those produced by legislatures; are fully determinate; efficiently balance OMOV constraints against respect for community; and are robust against manipulation. The chief downside is that some districts are discontinuous, although this is rare and could be mitigated even further. In the meantime, our algorithm provides a valuable safe harbor for States hoping to avoid future court challenges, an attractive model for reform legislation, and a transparent benchmark for exposing gerrymanders to public scrutiny.

Research Summary

In late 2014, California voters passed Proposition 47 that redefined a set of less serious felony drug and property offenses as misdemeanors. We examine how racial disparities in criminal court dispositions in San Francisco change in the years before (2010-2014) and after (2015-2016) the passage of Proposition 47. We decompose racial disparities in court dispositions into components due to racial differences in offense characteristics, involvement in the criminal justice system at the time of arrest, pretrial detention, criminal history, and the residual unexplained component. Before and after Proposition 47 case characteristics explain nearly all of the observable race disparities in court dispositions. However, after the passage of Proposition 47 there is a narrowing of racial disparities in convictions and incarceration sentences that is driven by lesser weight placed on criminal history, active criminal justice status, and pretrial detention in effecting court dispositions.

Policy Implications

The findings from this study suggest that policy reforms that scale back the severity of punishment for criminal history and active criminal justice status for less serious felony offenses may help narrow racial inequalities in criminal court dispositions. Efforts to reduce the impact of racial inequalities in mass incarceration in other states should consider reforms that reduce the weight that criminal history, pretrial detention, and active probation status has on criminal defendants’ eligibility for prison for less serious drug and property offenses.

Carbon offsets allow greenhouse gas emitters regulated under an emissions cap to comply by paying others outside of the capped sectors to reduce emissions. The first major carbon offset program, the United Nations’ Clean Development Mechanism (CDM), has been criticized for generating a large number of credits from projects that do not actually reduce emissions. Following the controversial CDM experience, California pioneered a second-generation compliance offset program that shifts the focus of quality control from assessments of individual projects to the development of offset protocols, which define eligibility criteria and methods for estimating emissions reductions for categories of projects. We assess how well California’s protocol-centered approach mitigates the risk of over-crediting greenhouse gas reductions. This analysis is relevant because the offset program could make up the full effect of the state’s cap-and-trade program through 2020, and half of its effect through 2030. We review the development of two of California’s offset protocols—Mine Methane Capture and Rice Cultivation—and examine the regulator’s treatment of three sources of uncertainty in emission reduction estimates that led to large-scale over-crediting under the CDM: determining additionality, estimating the counterfactual baseline scenario, and avoiding perverse incentives that inadvertently increase emissions.

We find that while the risk of over-crediting can be reduced through careful analysis, conservative design decisions, and ongoing monitoring of protocol outcomes, even best practices result in significant uncertainty in quantifying true emission reductions. Rather than eliminate the risk of overcrediting, California’s approach shifts risk from project-level to protocol-level quality assessments. To the extent that carbon pricing policies include large offset programs, as is the case in California, government priorities and methodological choices drive program outcomes, contrary to the common perception that carbon pricing policies mainly delegate decision-making to private actors. Ultimately, relying on carbon offsets to lower compliance costs risks lessening total emission reductions and increases uncertainty in whether an emissions target has been met. As a result, offsets can be understood as a way for regulated emitters to invest in an incentive program that achieves difficult-to-estimate emission reductions rather than as quantifiable and verifiable reductions equivalent to reductions under a cap. Substantial ongoing regulatory oversight is needed to contain uncertainty and avoid over-crediting.

We evaluate whether California’s state proposition 47 impacted state violent and property crime rates. Passed by the voters in November 2014, the proposition redefined many less serious property and drug offenses that in the past could be charged as either a felony or misdemeanor to straight misdemeanors. The proposition caused a sudden and sizable decline in county jail populations, a moderate decline in the state prison population, a decrease in arrests for property and drug offenses, and a wave of legal petitions filed for retroactive resentencing and reclassification of prior convictions. We make use of multiple strategies to estimate the effect of the proposition, including state-level synthetic cohort analysis, within-state event study estimates based on state-level monthly time series, and a cross-county analysis of changes in county-level crime rates that exploit heterogeneity in the effects of the proposition on local criminal justice practices. We find little evidence of an impact on violent crime rates in the state. Once changes in offense definitions and reporting practices in key agencies are accounted for, violent crime in California is roughly at pre-proposition levels and generally lower than the levels that existed in 2010 prior to a wave major reforms to the state’s criminal justice system. While our analysis of violent crime rates yields a few significant point estimates (a decrease in murder for one method and an increase in robbery for another), these findings are highly sensitivity to the method used to generate a counterfactual comparison path. We find more consistent evidence of an impact on property crime, operating primarily through an effect on larceny theft. The estimates are sensitive to the method used to generate the counterfactual, with more than half of the relative increase in property crime (and for some estimates considerably more) driven by a decline in the counterfactual crime rate rather than increases for California for several of the estimators that we employ. Despite this sensitivity, there is evidence from all methods tried that property crime increased with, a ballpark summary of five to seven percent roughly consistent with the totality of our analysis. Similar to violent crime, California property crime rates remain at historically low levels.

We develop empirically-grounded estimates of willingness-to-pay to avoid excess mortality risks caused by climate change. Using 40 countries' subnational data, we estimate a mortality-temperature relationship that enables global extrapolation to countries without data and projection of its future evolution, accounting for adaptation benefits. Further, we develop a revealed preference approach to recover unobserved adaptation costs. We combine these components with 33 high-resolution climate simulations, which produces a right-skewed distribution of global WTP with a mean of $38.1 per tCO2 under a high emissions scenario. Projections generally indicate increased mortality in today's poor locations and higher adaptation expenditures in rich ones.