This study investigates whether the response of stock returns to economic policy uncertainty de- pends on the level of government size in the economy. Although there is a consensus in the liter- ature that stock markets react negatively to policy-related uncertainties, the factors that determine the magnitude of this effect have been ignored. This study is the first to demonstrate that the magnitude of this effect depends on the size of the government in the economy. In the study, data for the period 1997Q1-2021Q4 pertaining to 18 countries are used. According to results of fixed-effects estimations with Driscoll-Kraay robust standard errors, economic policy uncer- tainty affects stock returns negatively. In addition, the coefficient of interaction term formed by the variables of policy uncertainty and government size is also negative and significant. These results indicate that the negative response of stock returns to policy uncertainty grows as gov- ernment size increases. The sensitivity analysis results show that the findings are not sensitive to the estimations made by alternative approaches and are therefore robust. The findings of the study contain important implications for policymakers. Investors can also benefit from the results at the point of international asset allocation against future policy-related uncertainties.

Keywords: Economic policy uncertainty, stock returns, government size, moderating effect, Driscoll-Kraay robust standard errors