Compare methods

	Historical National Accounting	Occupational Structure Reconstruction
Field	Economic History	Economic History
Family	Process / pipeline	Process / pipeline
Year of origin	1962	2010
Originator	Phyllis Deane and W. A. Cole; later Angus Maddison, Robert Allen, Stephen Broadberry	E. A. Wrigley and the Cambridge Group for the History of Population and Social Structure
Type	descriptive-reconstruction	descriptive-reconstruction
Seminal source	Maddison, A. (2007). Contours of the World Economy 1-2030 AD: Essays in Macro-Economic History. Oxford University Press. ISBN: 9780199227204	Wrigley, E. A. (2010). The PST System of Classifying Occupations. Cambridge Group for the History of Population and Social Structure.
Aliases	Historical GDP reconstruction, Pre-modern national accounts, Retrospective national accounting, Reconstructed historical accounts	PST occupational coding, Sectoral structure reconstruction, Primary-secondary-tertiary classification, Cambridge occupational structure
Related	3	3
Summary	Historical national accounting is the systematic reconstruction of a country's gross domestic product and its components for periods that predate official statistical offices. Where modern statisticians collect contemporaneous surveys, the historical accountant must assemble output from surviving fragments: tithe records, customs ledgers, probate inventories, guild accounts, harvest yields, and wage books. The method adapts the conventional output, income, and expenditure approaches of national accounting to the constraints of incomplete archival evidence, building value-added estimates sector by sector and reconciling them into an internally consistent whole. Pioneered for Britain by Deane and Cole and refined by Maddison, Allen, and the Broadberry school, it has produced annual GDP series stretching back to the medieval period. The resulting estimates anchor virtually all quantitative debate about long-run growth, the timing of the Industrial Revolution, and the Great Divergence between Europe and Asia.	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.