Air pollution’s harm to long-term health is now well known, but its immediate negative impact on human behaviour has only recently received attention. A growing body of academic research from economists finds that air pollution reduces worker productivity, impairs cognition, and increases violent crime. The impact of pollution on crime found in clean cities by global standards, such as Chicago and London, raises the question of whether the immediate impacts of air pollution are even worse in dirtier cities.
A recent study published in the Journal of Economic Behavior and Organization has unveiled substantial links between air pollution and crime rates in Almaty, the most populous city in Kazakhstan. In 2020, Almaty ranked among the top global cities with higher crime rates. The findings demonstrate that the increased impact of air pollution is driven by theft, which accounts for most of the city’s reported crimes. The results are consistent with the theory that air pollution distorts behaviour to discount future punishment. Consequently, motivation to clean up dirty cities should be driven by the long-term goal of increasing life expectancy and immediate economic improvement.
I love the mountains
Almaty’s proximity to mountains makes the city not only an excellent skiing destination (it narrowly lost to Beijing in voting to host the 2022 Winter Olympics), but it also helps create pollution variation crucial to identifying a causal relationship between air pollution and crime. When winds blow from the southeast, clean mountain air reaches the city. Mountains also contribute to temperature inversions, when cold air at lower elevations is trapped below hot air. Either condition creates a quasi-random variation in air pollution that does not otherwise relate to crime. Such variation is crucial because air pollution and crime may otherwise have common causes, such as increased human activity in a particular location.
The possibility of temperature inversions contributes to air pollution in Almaty, which is highly seasonal. In 2021, the city ranked in the 94th percentile of pollution overall but in the 98th percentile in the winter, according to IQAir.com. This measure is based on PM2.5, particulate matter of 2.5 microns in diameter or less that is small enough to affect the lungs and brain. Almaty still relies on centralised coal heating in the winter, thus increasing the concentrations of many pollutants.
Therefore, it was speculated that the seasonality of air pollution may also reduce awareness of air pollution in Almaty, so there is less action taken to avoid air pollution that would mitigate its impact. The study focuses on crime and PM2.5 pollution for three Almaty winters from December 2017 through March 2020.
Using daily data from Almaty’s districts and the random variation in mountain winds and temperature inversions, the research estimated pollution’s impact on crime as four times as large as that found in cleaner cities. When the data was disaggregated to focus on individual crimes, it found a more significant impact on property crime, especially theft, and no impact on violent crime. The findings are robust to various alternative specifications, including relating crime directly to the random variation in inversions and mountain winds at an 8-hour frequency. This specification captures the effects of pollutants other than PM2.5 and avoids any issues with the mismeasurement of PM2.5 air pollution.
How could air pollution cause more significant thefts? Rational economic decisions weigh immediate benefits against uncertain future costs, and air pollution can distort this calculation. Air pollution creates stress and discomfort, and experimental evidence points to stress-causing impatience and stress hormones, causing people to favour immediate gratification. Recent criminology literature also emphasises how crime occurs when criminals disregard their fear of getting caught.
Mounting evidence of air pollution’s economic harm
While increased thefts could be argued to be a minor social concern, we offer here several counterarguments. First, the study finds that the increase is driven more by major thefts than by petty thefts. Second, even petty thefts can result in tragic consequences: Denis Ten, the 2014 Olympic bronze medallist in Men’s singles Figure Skating, was stabbed to death in Almaty in July 2018 when he confronted carjackers stealing his car mirrors worth less than 70 U.S. dollars. Third, the increase in criminal behaviour points to a broader distortion in economic decision-making among residents of Almaty.
In November 2022, the European Bank for Reconstruction and Development (EBRD) approved a loan valued in local currency at 252 million Euros to replace coal with natural gas in Almaty’s largest power plant, a welcome investment in improving Almaty’s air quality. Yet, in the package assessing the positive social impacts of the project from reducing air pollution, the authors focused exclusively on air pollution’s harmful health consequences for Almaty.
Such impacts underestimate air pollution’s immediate economic harm, and they commit the fallacy of casting air pollution reduction as a trade-off between the fiscal costs of cleaner energy weighed against long-term health benefits. The research contributes to mounting evidence that the economic benefits of reducing air pollution should be important in development strategies.
This research was supported by the Nazarbayev University Social Policy Grant, “The Economic Consequences of Air Pollution”, awarded to David R. DeRemer.
Batkeyev, B., & DeRemer, D. R. (2023). Mountains of evidence: The effects of abnormal air pollution on crime. Journal of Economic Behavior & Organization, 210, 288-319. https://doi.org/10.1080/09669582.2020.1783276