手法を比較

	Shift-Share Analysis	Location Quotient	シフトシェア操作変数（Bartik操作変数）
分野	経済学	経済学	因果推論
系統	Process / pipeline	Process / pipeline	Regression model
提唱年	1960	1960	2020
提唱者	Edgar S. Dunn (Daniel Creamer credited with early use)	Developed in regional science; codified by Walter Isard	Bartik (1991); identification framework by Goldsmith-Pinkham, Sorkin & Swift (2020) and Borusyak, Hull & Jaravel (2022)
種類	Descriptive decomposition of regional growth	Descriptive index of relative regional concentration	Instrumental-variable design
原典	Dunn, E. S. (1960). A statistical and analytical technique for regional analysis. Papers of the Regional Science Association, 6(1), 97–112.	Isard, W. (1960). Methods of Regional Analysis: An Introduction to Regional Science. Cambridge, MA: MIT Press. ISBN: 9780262090032	Goldsmith-Pinkham, P., Sorkin, I. & Swift, H. (2020). Bartik Instruments: What, When, Why, and How. American Economic Review, 110(8), 2586–2624.
別名	Shift-Share Decomposition, SSA, Esteban-Marquillas Shift-Share, Regional Shift-Share	LQ, Coefficient of Localization, Regional Specialization Ratio	Bartik instrument, shift-share instrument, Shift-Share Araç Değişkeni (Bartik Instrument)
関連	3	3	5
概要	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.	The location quotient (LQ) is a simple descriptive index that measures how concentrated an industry is in a region relative to a larger reference area, usually the nation. It is the ratio of the industry's share of local employment (or output) to its share of national employment. An LQ above one means the region is more specialized in that industry than the nation as a whole; an LQ below one means it is under-represented.	The shift-share instrumental variable, widely known as the Bartik instrument, is a causal-inference strategy that builds an instrument by interacting national or sector-level shocks (the shifts) with local composition weights (the shares). Its modern identification framework was set out by Goldsmith-Pinkham, Sorkin and Swift (2020) and Borusyak, Hull and Jaravel (2022).