Is high-skilled migration harmful to tax systems' progressivity

Decreased transportation costs have led to the transmission of ideas and values across national borders that has helped reduce the barriers to international labor mobility. In this context, high-skilled individuals are more likely to vote with their feet in response to high income taxes. It is thus important to examine the magnitude of tax-driven migration responses in developed countries as well as the possible consequences of income tax competition between nation states. More specifically, how does the potential threat of migration affect a country's optimal income tax policies?