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I4R Discussion Paper Series #26


Carl Bonander (University of Gothenburg), Niklas Jakobsson (Karlstad University), Naimi Johansson (Region Örebro, Örebro University)

Reproduction and Replication Analyses of Andersson (2019): A Replication Report from the Toronto Replication Games

This report presents a replication of Andersson (2019) performed at the Toronto Replication Games in 2023. Andersson (2019) estimates the effect of carbon taxes on CO2 emissions in Sweden using the synthetic control method. His findings indicate a 10.9 percent reduction in emissions during the 1990-2005 period, which equates to –0.29 metric tons of CO2 per capita in an average year. The results from an in-space placebo test show that Sweden had the highest post/pre-mean squared prediction error (MSPE) ratio, resulting in a placebo-based p-value of 1/15=0.067. We successfully reproduce these findings and conduct a series of pre-specified replication analyses to examine how robust the findings are to model specification choices. We run 14 alternative specifications with various combinations of pre-treatment outcome values, with and without covariates. The median point estimate from our replication analyses is -0.28 metric tons of CO2 per capita (min: –0.34, max: –0.17). Placebo-based p-values are equal to 1/15=0.067 in seven specifications, 2/15=0.13 in six, and 4/15=0.27 in one.