Yuanning
Liang

Biodiversity loss is driven by multiple anthropogenic pressures, including climate change, habitat loss, and environmental pollution. Climate policies that promote the development of renewable energy reduce one of these pressures by lowering greenhouse gas emissions. Yet large-scale energy infrastructure can intensify habitat-related pressures when it converts or fragments land. The transition to renewable energy therefore requires the appropriate siting and operating decisions that achieve carbon emissions reductions while avoiding unnecessary biodiversity losses. On page 831 of this issue, Zhang et al. (1) show that policy-driven solar expansion in China reduced local bird diversity. The study extends renewable-energy policy evaluation beyond direct emissions reductions by documenting an unintended adverse effect on biodiversity. The broader implication is that biodiversity impacts should directly enter the implementation and assessment of renewable-energy policies.

Human activities increasingly disrupt ecosystems, yet the economic costs of energy infrastructure on migratory species remain underexplored. Using over 200 million GPS tracking records of migratory birds and a national database of Chinese power plants from 2014 to 2022, we show that plant construction significantly reduces bird stopover duration by 54.4% within 50 km, with effects that persist over years. Plant decommissioning generates ecological recovery, though the magnitude is smaller. We identify habitat alterations, air pollution, and water pollution as key mechanisms underlying these effects. By quantifying the economic consequences of energy infrastructure on migratory birds, this study advances the integration of biodiversity impacts into economic research.

The environmental impacts of economic activities extend beyond those directly affecting humans. This paper provides new evidence on the link between economic activity and ecosystem decline using a novel dataset that compiles longitudinal ecological sampling information at tens of thousands of locations across the United States between 1960 and 2015. Local shocks in economic activities, such as those driven by national military buildups, led to a significant reduction in species abundance, diversity, and stability, with one-third of the observed effects explained by the causal impact of air pollution. Government environmental regulations significantly mitigated pollution externalities.

Massive wildlife losses over the past 50 y have brought new urgency to identifying both the drivers of population decline and potential solutions. We provide large-scale evidence that air pollution, specifically ozone, is associated with declines in bird abundance in the United States. We show that an air pollution regulation limiting ozone precursors emissions has delivered substantial benefits to bird conservation. Our estimates imply that air quality improvements over the past 4 decades have stemmed the decline in bird populations, averting the loss of 1.5 billion birds, ∼20% of current totals. Our results highlight that in addition to protecting human health, air pollution regulations have previously unrecognized and unquantified conservation cobenefits.

Ecosystem restoration is increasingly promoted as a global strategy to combat biodiversity loss, climate change, and environmental degradation (1-3). Yet robust empirical evidence for long-term, cost-effective recovery at national scales remains limited (4). Critics also emphasize that restoration outcomes are often context-dependent and that trade-offs and costs are poorly quantified (5,6). Here we show that China’s ecological reforestation programs (ERPs) generated substantial ecological and public health benefits including climate extremes mitigation, air and water quality improvements, and biodiversity recovery, all without compromising agricultural productivity. Over two decades, monetized health gains from the ERPs exceeded program costs ten times over. Using China as an empirical benchmark, we construct a global return-on-investment map for forest restoration. This projection identifies regions where reforestation could yield comparably high returns.

Ecosystem services are essential to economic activity, yet their social value is difficult to quantify since markets rarely internalize the externalities they generate. This paper provides causal evidence on the economic value of ecosystem services by studying bees, the primary pollinators in modern agriculture. Assembling comprehensive data on U.S. agriculture and bee colonies, we construct a county-by-year measure of local bee services that combines variation in regional bee supply, crop-specific pollination demand, and local crop structure, and link it to agricultural outcomes. To address endogeneity, we develop a novel instrumental-variables strategy that exploits non-local ecological shocks transmitted through seasonal bee movements. We show that an additional colony raises annual net farm income by about $5,000, an order of magnitude above observed rental fees. This value varies systematically with colony conditions before transport and pollination demand where colonies are deployed. Beyond agricultural income, managed bee services also increase wild bee diversity. Our estimates provide a benchmark for ecosystem service benefit-cost analysis and underscore the importance of seasonal movements for targeting place-based conservation policies.

Regulatory efforts to mitigate public hazards can be undermined when agents respond strategically to enforcement. This paper evaluates the impact of a nationwide commercial vehicle inspection program on road safety, using comprehensive data on inspections and accidents. The findings reveal a sharp increase in a given truck’s accident rate immediately following an inspection-driven by reduced caution from recently inspected drivers, such as speeding and neglecting vehicle maintenance, due to the low likelihood of repeated inspections. Comparative policy analysis indicates that less predictable inspection schedules and practices could mitigate these adverse behavioral responses.

This paper measures the impact of housing price changes on household consumption at the city level using the universe of credit and debit card transactions in China from 2011 to 2013. In sharp contrast to the literature on the US housing market, our analysis shows a large and negative housing price elasticity of consumption: a 10% increase in housing prices would lead to a 9% reduction in non-housing spending. We argue that the negative elasticity is driven by the combination of a strong investment incentive in housing and heavy borrowing constraints faced by households. This finding is corroborated by the fact that households increase their savings as housing prices increase. Our analysis suggests that the negative impact of housing price increases on consumption was an important factor behind the low growth rate in household consumption relative to the growth of disposal income during the sample period.

This paper examines whether decentralizing local legislative authority improves environmental governance. Using China’s expansion of municipal lawmaking powers, it estimates how local authority affects pollution control and studies the institutional conditions under which decentralization strengthens policy implementation.