Shift-Share Analysis

Shift-share analysis is a descriptive technique that decomposes the change in a regional variable — most often sectoral employment — into three additive components: the part attributable to overall national growth, the part attributable to the region's industry mix, and the part attributable to the region's own competitive performance. Formalized by Edgar Dunn in 1960, it answers whether a region grew because the national economy grew, because it specializes in fast-growing industries, or because its industries outperformed (or underperformed) their national counterparts.