Unconditional convergence

"Unlike economies as a whole, manufacturing industries exhibit unconditional convergence in labor productivity. The paper documents this finding for 4-digit manufacturing sectors for a large group of developed and developing countries over the period since 1990. The coefficient of unconditional convergence is estimated quite precisely and is large, at 3.0-5.6 percent per year depending on the estimation horizon. The result is robust to a large number of specification tests, and statistically highly significant. Because of data coverage, these findings should be as viewed as applying to the organized, formal parts of manufacturing"--National Bureau of Economic Research web site.