02243cam a22002777 4500001000600000003000500006005001700011008004100028100002300069245015900092260006600251490005100317500001600368520098500384530006101369538007201430538003601502690005701538690012701595700002101722700002101743710004201764830008601806856003701892856003601929t0178NBER20150330095842.0150330s1995 mau||||fs|||| 000 0 eng d1 aAngrist, Joshua D.10aNon-Parametric Demand Analysis with an Application to the Demand for Fishh[electronic resource] /cJoshua D. Angrist, Kathryn Graddy, Guido W. Imbens. aCambridge, Mass.bNational Bureau of Economic Researchc1995.1 aNBER technical working paper seriesvno. t0178 aApril 1995.3 aInstrumental variables (IV) estimation of a demand equation using time series data is shown to produce a weighted average derivative of heterogeneous potential demand functions. This result adapts recent work on the causal interpretation of two-stage least squares estimates to the simultaneous equations context and generalizes earlier research on average derivative estimation to models with endogenous regressors. The paper also shows how to compute the weights underlying IV estimates of average derivatives in a simultaneous equations model. These ideas are illustrated using data from the Fulton Fish market in New York City to estimate an average elasticity of wholesale demand for fresh fish. The weighting function underlying IV estimates of the demand equation is graphed and interpreted. The empirical example illustrates the essentially local and context-specific nature of instrumental variables estimates of structural parameters in simultaneous equations models. aHardcopy version available to institutional subscribers. aSystem requirements: Adobe [Acrobat] Reader required for PDF files. aMode of access: World Wide Web. 7aC30 - General2Journal of Economic Literature class. 7aL66 - Food • Beverages • Cosmetics • Tobacco • Wine and Spirits2Journal of Economic Literature class.1 aGraddy, Kathryn.1 aImbens, Guido W.2 aNational Bureau of Economic Research. 0aTechnical Working Paper Series (National Bureau of Economic Research)vno. t0178.4 uhttp://www.nber.org/papers/t017841uhttp://dx.doi.org/10.3386/t0178