Growth, welfare and optimal trade taxes: a fallacy of composition

Optimal export taxation rules out the possibility of immiserizing growth in a two-country world. Thus, productivity increases in the exporting sector must be welfare improving. This paper shows that in a multicountry world such reasoning commits a fallacy of composition. Simultaneous growth of exporting nations can lead to welfare losses in the presence of unilaterally optimal export taxes. Also, optimal export taxes can decline in response to such growth. This result further strengthens the possibility of perverse welfare movements. Thus, standard policy recommendations of increasing productivity in the exporting sector may lead to unintended and self-defeating outcomes.