differences between national or regional productivity growth rates, when there are constant static returns to scale in production … account for permanent international productivity growth differentials. An alternative mechanism is the nontradedness of an …

persistence of productivity growth differentials between nations despite a common technology, constant returns to scale and … specification. The source of productivity (growth) differentials in our model is the existence of a non-traded capital good ('human … consider the influence on productivity growth differentials of private thrift, public debt, the taxation of capital and savings …