They include high levels of labor mobility, high levels of capital mobility, a system of transfers that shares risks across the region, and coordinated business cycles. (carnegieendowment.org)
Enforcing the residency system nationally could severely limit labor mobility in China. (carnegieendowment.org)
And on both counts it was obvious that Europe fell far short of the U.S. example, with limited labor mobility and virtually no fiscal integration. (krugman.blogs.nytimes.com)