We evaluated a program of payments for ecosystem services in Uganda that offered forest-owning households annual payments of 70,000 Ugandan shillings per hectare if they conserved their forest. The program was implemented as a randomized controlled trial in 121 villages, 60 of which received the program for 2 years. The primary outcome was the change in land area covered by trees, measured by classifying high-resolution satellite imagery. We found that tree cover declined by 4.2% during the study period in treatment villages, compared to 9.1% in control villages. We found no evidence that enrollees shifted their deforestation to nearby land. We valued the delayed carbon dioxide emissions and found that this program benefit is 2.4 times as large as the program costs.

Social distancing remains an important strategy to combat the COVID-19 pandemic in the United States. However, the impacts of specific state-level policies on mobility and subsequent COVID-19 case trajectories have not been completely quantified. Using anonymized and aggregated mobility data from opted-in Google users, we found that state-level emergency declarations resulted in a 9.9% reduction in time spent away from places of residence. Implementation of one or more social distancing policies resulted in an additional 24.5% reduction in mobility the following week, and subsequent shelter-in-place mandates yielded an additional 29.0% reduction. Decreases in mobility were associated with substantial reductions in case growth two to four weeks later. For example, a 10% reduction in mobility was associated with a 17.5% reduction in case growth two weeks later. Given the continued reliance on social distancing policies to limit the spread of COVID-19, these results may be helpful to public health officials trying to balance infection control with the economic and social consequences of these policies.

Background Social distancing have been widely used to mitigate community spread of SARS-CoV-2. We sought to quantify the impact of COVID-19 social distancing policies across 27 European counties in spring 2020 on population mobility and the subsequent trajectory of disease. Methods We obtained data on national social distancing policies from the Oxford COVID-19 Government Response Tracker and aggregated and anonymized mobility data from Google. We used a pre-post comparison and two linear mixed-effects models to first assess the relationship between implementation of national policies and observed changes in mobility, and then to assess the relationship between changes in mobility and rates of COVID-19 infections in subsequent weeks. Results Compared to a pre-COVID baseline, Spain saw the largest decrease in aggregate population mobility (~70%), as measured by the time spent away from residence, while Sweden saw the smallest decrease (~20%). The largest declines in mobility were associated with mandatory stay-at-home orders, followed by mandatory workplace closures, school closures, and non-mandatory workplace closures. While mandatory shelter-in-place orders were associated with 16.7% less mobility (95% CI: -23.7% to -9.7%), non-mandatory orders were only associated with an 8.4% decrease (95% CI: -14.9% to -1.8%). Large-gathering bans were associated with the smallest change in mobility compared with other policy types. Changes in mobility were in turn associated with changes in COVID-19 case growth. For example, a 10% decrease in time spent away from places of residence was associated with 11.8% (95% CI: 3.8%, 19.1%) fewer new COVID-19 cases. Discussion This comprehensive evaluation across Europe suggests that mandatory stay-at-home orders and workplace closures had the largest impacts on population mobility and subsequent COVID-19 cases at the onset of the pandemic. With a better understanding of policies’ relative performance, countries can more effectively invest in, and target, early nonpharmacological interventions.

The impact of armed conflict on the environment is of major public policy importance. We use a geographically disaggregated dataset of civil war violence together with satellite imagery of land cover to test whether war facilitated or prevented forest loss in Sierra Leone. The conflict data set allows us to establish where rebel groups were stationed and where battles and attacks occurred. The satellite data enables to us to monitor the change in forest cover (total, primary, and secondary) in all of Sierra Leone's 151 chiefdoms, between 1990 (prior to the war) and 2000 (just prior to its end). The results suggest that conflict in Sierra Leone acted as a brake on local deforestation: conflict-ridden areas experienced significantly less forest loss relative to their more conflict-free counterparts. OPEN ACCESS RECEIVED

This paper evaluates a Payments for Ecosystem Services (PES) program in western Uganda that offered forest-owning households cash payments if they conserved their forest. The program was implemented as a randomized trial in 121 villages, 60 of which received the program for two years. The PES program reduced deforestation and forest degradation: Tree cover, measured using high-resolution satellite imagery, declined by 2% to 5% in treatment villages compared to 7% to 10% in control villages during the study period. We find no evidence of shifting of treecutting to nearby land. We then use the estimated effect size and the "social cost of carbon" to value the delayed carbon dioxide emissions, and compare this benefit to the program's cost.1 behaviors (Ferraro and Kiss, 2002;Wunder, 2007;Engel, Pagiola, and Wunder, 2008). PES is the environmental version of a well-known policy instrument in developing countries, conditional cash transfers (CCTs), which are more commonly used to promote child health and education.Despite the widespread use and growing popularity of PES, its effectiveness and costeffectiveness are open questions. Individuals might be unresponsive to the incentives, leading to small impacts. In addition, even if some people respond to the incentives, cost-effectiveness could be low if, absent the payments, many participants would have engaged in the incentivized behavior anyway. In the case of PES, this problem of inframarginality is often called "additionality": How much additional forest cover does a PES program actually cause? Another concern is that individuals will simply shift their tree-cutting from land covered by the PES contract to other nearby land.This paper is a randomized evaluation of a PES intervention that was piloted precisely to measure the causal impacts on forest cover. The PES program offered private owners of forestland in western Uganda payments if they refrained from clearing trees. The program was designed and implemented by a local non-governmental organization (NGO). The study was carried out in 121 villages with private forest owners (PFOs); 60 of the villages were randomly selected to be in the treatment group. In treatment villages, the PES program was marketed to PFOs and they were eligible to enroll. Over the two-year pilot program from 2011 to 2013, for each hectare of forest they owned, enrollees received 70,000 Ugandan shillings (UGX), or $28 in 2012 US dollars, per year if they complied with the contract. 3 The implementing NGO employed forest monitors who conducted spot checks of enrollees' land to check for recent tree-clearing. The program also offered additional payments in exchange for planting tree seedlings.We measure the impact of the program on forest cover by analyzing satellite imagery.Specifically, we tasked a very high resolution commercial satellite, QuickBird, to take images of the study region at baseline and endline and classified each pixel as tree-covered or not 3 The average exchange rate during the study period was approximately 2500 UGX = 1 US ...