Compare methods

	Input-Output Analysis	Location Quotient	Shift-Share IV
Field	Economics	Economics	Causal inference
Family	Process / pipeline	Process / pipeline	Regression model
Year of origin	1936	1960	2020
Originator	Wassily Leontief	Developed in regional science; codified by Walter Isard	Bartik (1991); identification framework by Goldsmith-Pinkham, Sorkin & Swift (2020) and Borusyak, Hull & Jaravel (2022)
Type	Linear inter-industry accounting and impact model	Descriptive index of relative regional concentration	Instrumental-variable design
Seminal source	Leontief, W. W. (1936). Quantitative input and output relations in the economic system of the United States. The Review of Economics and Statistics, 18(3), 105–125.	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.
Aliases	Leontief Model, Inter-Industry Analysis, I-O Analysis, Input-Output Model	LQ, Coefficient of Localization, Regional Specialization Ratio	Bartik instrument, shift-share instrument, Shift-Share Araç Değişkeni (Bartik Instrument)
Related	4	3	5
Summary	Input-output analysis is a quantitative framework for representing the interdependence between the industries of an economy, introduced by Wassily Leontief in 1936. It records the flows of goods and services between sectors in a transactions table, derives fixed technical coefficients describing how much each industry buys from every other industry per unit of output, and inverts the resulting linear system to trace how an exogenous change in final demand ripples through the entire production structure.	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).