Do competitive markets encourage tax aggressiveness?

We investigate whether industry-level product market competition and firm-level market leadership affect firms' tax aggressiveness. Studying competition from both current market participants and potential entrants, and using a market share-based measure of market leadership, we find that firms facing higher competition from current market participants engage in more tax aggressiveness. We further find that market-following firms — rather than market‑leading firms — engage in relatively more tax aggressiveness within these higher competition settings. Our results contrast with most political and regulatory anecdotes that target market‑leading firms for aggressive tax behaviors, and add to the ongoing policy debates on tax incidence. Our main findings and additional tests are consistent with the view that market‑leading firms in imperfectively competitive product markets are able to pass on tax costs to customers, while market-following firms in crowded industries are pressured to engage in tax aggressiveness because they cannot pass on tax costs.