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 CO 2 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 CO 2 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 CO 2 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.