Occupational Structure Reconstruction

Occupational structure reconstruction uses the distribution of the workforce across economic activities to chart how an economy's sectoral composition evolved before modern statistics. The Cambridge Group, led by E. A. Wrigley, developed the Primary-Secondary-Tertiary (PST) system, a classification purpose-built for historical occupational descriptors that sorts every recorded occupation into agriculture and extraction (primary), manufacturing and processing (secondary), or trade, transport, and services (tertiary), with finer subdivisions beneath. By coding occupations from censuses, parish registers, probate inventories, trade directories, and militia lists, the method estimates the share of workers in each sector and tracks its movement across benchmark years. Because the shift from primary to secondary and tertiary employment is the structural signature of economic development, these reconstructions illuminate the timing and geography of industrialization with a directness that aggregate output figures cannot match, complementing and constraining national-accounting estimates of growth.