Sigma Convergence Versus Beta Convergence: Evidence from County-level Data
This note outlines: 1) Why sigma-convergence may not accompany beta-convergence; 2) Cites evidence of beta-convergence in the U.S.; 3) Demonstrates that sigma-convergence does not hold across the U.S. or within most U.S. states; and 4) Demonstrates the robustness of this finding to increases in mean income. The distributions of shocks appear important towards accounting for income disparity.