RDP 9110: Resource Convergence and Intra-Industry Trade Equation (12)

D_{i j}^{t *} (R) = | \frac{R_{i}^{t} - R_{j}^{t}}{{\bar{R}}^{t}} |; \bar{R^{t}} = \sum_{m = 1}^{22} [\frac{G N P_{m}^{t}}{\sum_{m = 1}^{22} G N P_{m}^{t}}] R_{m}^{t}