Mismatch and Assimilation
Income disparity across countries has been large and widening over time. We develop a tractable model where factor requirements in production technology do not necessarily match a country's factor input profile. Appropriate assimilation of frontier technologies balances such multi-dimensional factor input-technology mismatch, thus mitigating the efficiency loss. This yields a new measure for endogenous TFP, entailing a novel trade-off between a country's income level and income growth that depends critically on the assimilation ability and the factor input mismatch. Our baseline model accounts for 80%-92% of the global income variation over the past 50 years. The widening of mismatch and heterogeneity in the assimilation ability account for 41% and 20% of the global growth variation, whereas physical capital accounts for about one third with human capital largely inconsequential. In particular, about 30% of the output growth in miracle Asian economies comes from narrowing the gap arisen from mismatch, and 94% of the growth stagnation in trapped African economies due to the widening mismatch. A country may fall into a middle-income trap after a factor advantage reversal that changes the pattern of mismatch.