Germany’s Low Emission Zones (LEZs) have improved air quality by driving older diesel vehicles off the street, according to a paper co-authored by Hertie School Professor of Economics Christian Traxler.
You can find them in London, Paris, Brussels and Berlin – Low Emission Zones (LEZs) have been introduced in the last decades all over the world as an effort to curb carbon emissions and reduce air pollution in urban areas. A new IZA (Institute of Labor Economics) discussion paper, co-authored by Christian Traxler, Professor of Economics at the Hertie School, alongside scholars Eren Aydin (University of Hamburg) and Markus Gehrsitz (University of Strathclyde), investigates the impact of more than 70 LEZs in Germany on air pollution, traffic volumes and vehicle fleet composition.
Small changes, big impact
“We confirm earlier evidence that Low Emission Zones have a positive impact on air quality in urban centres, causing a significant decline in fine dust, or particulate matter (PM10),” Christian Traxler says. Most importantly, their work shows how even a small decrease in the number of older diesel cars has significantly reduced harmful air pollution as a direct consequence of LEZs.
The analysis indicates that changes in the local vehicle fleet composition are the primary driver of pollution reduction. LEZs prompted the replacement of approximately 50,000 older, emission-intensive diesel vehicles with newer, cleaner gasoline cars. These replacements resulted in substantial reductions in tailpipe PM10 emissions, with modern gasoline cars emitting 94-98% less PM10 per kilometre than the older diesel vehicles they replaced.
Lower social costs than expected
The paper concludes that LEZs not only achieved short-term air quality improvements but also had lower social costs than previously estimated.
The nuanced but significant shifts in fleet composition highlight the effectiveness of LEZs in reducing urban air pollution, primarily through the targeted replacement of high-emission vehicles with cleaner alternatives.
The researchers hope future research explores the cost-effectiveness of LEZs at varying levels of stringency and their long-term impacts on urban air quality and public health.
Link to paper: Greener Fleet, Cleaner Air: How Low Emission Zones Reduce Pollution | IZA - Institute of Labor Economics
About the study
The paper “Greener Fleet, Cleaner Air: How Low Emission Zones Reduce Pollution”, which was released in the Institute of Labor Economics (IZA) discussion paper series, investigates the impact of Low Emission Zones (LEZs) in Germany on air pollution, traffic volumes and vehicle fleet composition. Christian Traxler, Professor of Economics at the Hertie School, alongside co-authors Eren Aydin (University of Hamburg) and Markus Gehrsitz (University of Strathclyde), study the effects of LEZs in Germany, where more than 70 cities have introduced zones in different stages: in Stage 1 LEZs banned vehicles with the lowest (Euro 1) emission standard; in Stages 2 and 3 LEZs also restricted vehicles meeting higher standards (Euro 2 and 3, respectively). Utilising a stacked differences-in-differences approach, the study examines the effects of different stages of LEZs, which progressively banned more polluting vehicles from city centres.
The Hertie School is not responsible for any content linked or referred to from these pages.
More about our expert
-
Christian Traxler, Professor of Economics