Unwatched Pollution: The Effect of Intermittent Monitoring on Air Quality

Intermittent monitoring of environmental standards may induce strategic changes in polluting activities. This paper documents local strategic responses to a cyclical, once-every-six-day air quality monitoring schedule under the federal Clean Air Act. Using satellite data of monitored areas, I show that air quality is significantly worse on unmonitored days. This effect is explained by short-term suppression of pollution on monitored days, especially during high-pollution periods when the city’s noncompliance risk is high. Cities’ use of air quality warnings increases on monitored days, which suggests local governments’ role in coordinating emission reductions. (JEL K32, Q35, Q58, R11)

Valuing Clean Air

The passage of the Clean Air Act and the creation of the Environmental Protection Agency (EPA) in 1970 marked a sweeping transformation in American politics. In a few short years, the environmental movement pushed Republican and Democratic elected officials to articulate a right to clean air as part of a bevy of new federal guarantees. Charged with delivering on those promises, the EPA represented a bold assertion that the federal government had a responsibility to protect the environment, the authority to command private business to reduce their pollution, and the capacity to dictate how they did so. But revolutions are always contested and the starburst of environmental concern that propelled the Clean Air Act and the EPA coincided with economic convulsions that shook the liberal state to its core. As powerful businesses pressed to roll back regulations, elected officials from both parties questioned whether the nation could keep its environmental promises. Pushing on, the EPA adopted a monetized approach to environmental value that sat at odds with environmentalist notions of natural rights but provided a critical shield for the agency’s rulemaking, as environmental protection came to serve as a key battleground in larger debates over markets, government, and public welfare. The EPA’s success and the potential limits of its monetary approach are evident in the very air we breathe today—far cleaner and healthier as a result of the EPA’s actions, but holding new threats in a rapidly changing climate.

Clean Air Act mitigate the cognitive deterioration in older adults

Air pollution may accelerate cognitive aging, it is unclear whether large-scale interventions by Clean Air Act can mitigate the cognitive deterioration. Here, we conducted a difference-in-differences analysis based on Chinese Longitudinal Healthy Longevity Survey during 2014 and 2018. Intervention group came from where the government set a strict target of reducing air pollution, whereas control group lived in areas without reduction target. Global cognitive functions were measured using the Mini-Mental State Examination (MMSE). We found the intervention group with implementing Clean Air Act had a significantly smaller decline in MMSE score compared to the control group. Interquartile increases in PM2.5 and SO2 concentrations were significantly associated with a faster decline of MMSE score by 1.78 and 0.92 points, respectively. Implementing stringent clean air policies, especially in low- and middle-income countries may mitigate the risk of cognitive aging in older people.

Effectiveness of SOx, NOx, and Primary Particulate Matter Control Strategies in the Improvement of Ambient PM Concentration in Taiwan

The Community Multiscale Air Quality (CMAQ) measurement was employed for evaluating the effectiveness of fine particulate matter control strategies in Taiwan. There are three scenarios as follows: (I) the 2014 baseline year emission, (II) 2020 emissions reduced via the Clean Air Act (CAA), and (III) other emissions reduced stringently via the Clean Air Act. Based on the Taiwan Emission Data System (TEDs) 8.1, established in 2014, the emission of particulate matter 2.5 (PM2.5) was 73.5 thousand tons y−1, that of SOx was 121.3 thousand tons y−1, and that of NOx was 404.4 thousand tons y−1 in Taiwan. The CMAQ model simulation indicated that the PM2.5 concentration was 21.9 μg m−3. This could be underestimated by 24% in comparison with data from the ambient air quality monitoring stations of the Taiwan Environmental Protection Administration (TEPA). The results of the simulation of the PM2.5 concentration showed high PM2.5 concentrations in central and southwestern Taiwan, especially in Taichung and Kaohsiung. Compared to scenario I, the average annual concentrations of PM2.5 for scenario II and scenario III showed reductions of 20.1% and 28.8%, respectively. From the results derived from the simulation, it can be seen that control of NOx emissions may improve daily airborne PM2.5 concentrations in Taiwan significantly and control of directly emitted PM2.5 emissions may improve airborne PM2.5 concentrations each month. Nevertheless, the results reveal that the preliminary control plan could not achievethe air quality standard. Therefore, the efficacy and effectiveness of the control measures must be considered to better reduce emissions in the future.

The health consequences of excess emissions: Evidence from Texas

Excess emissions are air pollution releases that exceed permitted levels and occur during facility start-ups, shutdowns, or malfunctions. While they are violations of the federal Clean Air Act, states have historically granted violating facilities automatic exemptions; limiting enforcement and weakening existing regulation. Recent efforts to harmonize state and federal rules have ignited debate surrounding optimal excess emissions regulation. Using Texas data from 2002-2017, we show robust evidence on the costs of excess emissions. We find that excess emissions increase harmful nearby pollution and elderly mortality, and are responsible for an average of 35 annual deaths in Texas alone. Using excess emissions as an instrument for ozone concentrations, we find that a 10% increase in monthly average ozone increases elderly mortality by 3.9%, driven by increased deaths in the oldest age groups.

Corporate Political Connections and Favorable Environmental Regulatory Enforcement

We examine whether the Environmental Protection Agency (EPA) uniformly enforces the Clean Air Act for politically connected and unconnected firms using a close election setting. We find no difference in regulated pollutant emissions or EPA investigations between the two groups, although connected firms experience less regulatory enforcement and lower penalties. These results are more pronounced for firms connected to politicians capable of influencing regulatory bureaucrats and for connected firms that are more important to their supported politicians. Taken together, our results show that campaign contributions can indirectly benefit firms by way of reduced environmental regulatory enforcement and penalties. This paper was accepted by Colin Mayer for the Special Issue of Management Science: Business and Climate Change.