This repository contains the code and manuscript accompanying the paper "Impact of Berlin's €29 ticket on Air Pollution: A quasi-experimental analysis". The full paper can be found at (Riaz,2023)
As part of the German Federal Climate Change Act and the Federal Immission Control Act, Germany has to cut down its GHG emissions and air pollutants by precise amounts. This requires policy design and evaluation to be objective and evidence based. Unfortunately, data limitations, competing policies and ethical concerns do not always provide the luxury to be able to do so. The introduction of the €29 ticket in Berlin provides a unique opportunity of conducting a causal evaluation of the transport subsidy’s impact on reducing emissions and air pollutants. Berlin was the only city in Germany that implemented a transport subsidy post the national €9 ticket. This paper leverages on that opportunity and uses quasi-experimental techniques to measure reduction in air pollution. For this purpose, data on air pollutants, fuel prices, weather parameters and a series of other temporal and spatial covariates was compiled for 18 German cities, at 90 unique geo-locations all geographically and temporally matched and of an hourly granularity from 1st September 2021 to 31st March 2023. Key properties of a set of atmospheric pollutants were analyzed in the context of road transport to form a reasonable hypothesis on how reduction in private transport could impact them. Using a Differences-in-Difference approach a reduction of about 2% in both Nitrogen Dioxide (NO2) and Carbon Monoxide (CO) and a reduction of 4% in Particulate Matter 10 (PM10) levels was observed as a result of the €29 ticket. These findings were further supported by employing a Synthetic Control approach following the works of (Abadie, Diamond, & Hainmueller, 2010) and (Abadie, Diamond, & Hainmueller, 2015). No evidence was observed on the reduction of ground level ozone (O3) by either of the approaches though this may just be because the chemical properties of this gas requires an alternate experimental design for its analysis. The findings of this study have important implications for achieving climate and environmental targets, providing transparency of policy impact to the taxpayers, and shaping future policy design by understanding what works and what doesn’t.