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Projection-Based Statistical Inference in Linear Structural Models with Possibly Weak Instruments

Listed author(s):
  • Jean-Marie Dufour
  • Mohamed Taamouti

It is well known that standard asymptotic theory is not valid or is extremely unreliable in models with identification problems or weak instruments [Dufour (1997, Econometrica), Staiger and Stock (1997, Econometrica), Wang and Zivot (1998, Econometrica), Stock and Wright (2000, Econometrica), Dufour and Jasiak (2001, International Economic Review)]. One possible way out consists here in using a variant of the Anderson-Rubin (1949, Ann. Math. Stat.) procedure. The latter, however, allows one to build exact tests and confidence sets only for the full vector of the coefficients of the endogenous explanatory variables in a structural equation, which in general does not allow for individual coefficients. This problem may in principle be overcome by using projection techniques [Dufour (1997, Econometrica), Dufour and Jasiak (2001, International Economic Review)]. Artypes are emphasized because they are robust to both weak instruments and instrument exclusion. However, these techniques can be implemented only by using costly numerical techniques. In this paper, we provide a complete analytic solution to the problem of building projection-based confidence sets from Anderson-Rubin-type confidence sets. The latter involves the geometric properties of "quadrics"" and can be viewed as an extension of usual confidence intervals and ellipsoids. Only least squares techniques are required for building the confidence intervals. We also study by simulation how ""conservative"" projection-based confidence sets are. Finally, we illustrate the methods proposed by applying them to three different examples: the relationship between trade and growth in a cross-section of countries, returns to education, and a study of production functions in the U.S. economy." L'une des questions les plus étudiées récemment en économétrie est celle des modèles présentant des problèmes de quasi non-identification ou d'instruments faibles. L'une des conséquences importantes de ce problème est la non validité de la théorie asymptotique standard [Dufour (1997, Econometrica), Staiger et Stock (1997, Econometrica), Wang et Zivot (1998, Econometrica), Stock et Wright (2000, Econometrica), Dufour et Jasiak (2001, International Economic Review)]. Le défi majeur dans ce cas consiste à trouver des méthodes d'inférence robustes à ce problème. Une solution possible consiste à utiliser la statistique d'Anderson-Rubin (1949, Ann. Math. Stat.). Nous mettons l'emphase sur les procédures de type Anderson-Rubin, car celles-ci sont robustes tant à la présence d'instruments faibles et à l'exclusion d'instruments. Cette dernière ne fournit cependant des tests exacts que pour les hypothèses spécifiant le vecteur entier des coefficients des variables endogènes dans un modèle structurel, et de façon correspondante, que des régions de confiance simultanées pour ces coefficients. Elle ne permet pas de tester des hypothèses spécifiant des coefficients individuels ou sur des transformations de ces coefficients. Ce problème peut être résolu en principe par des techniques de projection [Dufour (1997, Econometrica), Dufour et Jasiak (2001, International Economic Review)]. Cependant , ces techniques ne sont pas toujours faciles à appliquer et requièrent en général l'emploi de méthodes numériques. Dans ce texte, nous proposons une solution explicite complète au problème de la construction de régions de confiance par projection basées sur des statistiques de type Anderson-Rubin. Cette solution exploite les propriétés géométriques des "quadriques"" et peut s'interpréter comme une extension des intervalles et ellipsoïdes de confiance usuels. Le calcul de ces régions ne requièrent que des techniques de moindres carrés. Nous étudions également par simulation le degré de conservatisme des régions de confiance obtenues par projection. Enfin, nous illustrons les méthodes proposées par trois applications différentes: la relation entre l'ouverture commerciale et la croissance, le rendement de l'éducation et une étude sur les rendement d'échelles dans l'économie américaine."

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Paper provided by CIRANO in its series CIRANO Working Papers with number 2003s-39.

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Length: 52 pages
Date of creation: 01 May 2003
Handle: RePEc:cir:cirwor:2003s-39
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  1. Basu, Susanto & Fernald, John G., 1995. "Are apparent productive spillovers a figment of specification error?," Journal of Monetary Economics, Elsevier, vol. 36(1), pages 165-188, August.
  2. Maddala, G S & Jeong, Jinook, 1992. "On the Exact Small Sample Distribution of the Instrumental Variable Estimator," Econometrica, Econometric Society, vol. 60(1), pages 181-183, January.
  3. Benoit Perron, 2003. "Semiparametric Weak-Instrument Regressions with an Application to the Risk-Return Tradeoff," The Review of Economics and Statistics, MIT Press, vol. 85(2), pages 424-443, May.
  4. Dufour, Jean-Marie, 1989. "Nonlinear Hypotheses, Inequality Restrictions, and Non-nested Hypotheses: Exact Simultaneous Tests in Linear Regressions," Econometrica, Econometric Society, vol. 57(2), pages 335-355, March.
  5. Irwin, Douglas A. & Tervio, Marko, 2002. "Does trade raise income?: Evidence from the twentieth century," Journal of International Economics, Elsevier, vol. 58(1), pages 1-18, October.
  6. Donald, Stephen G & Newey, Whitney K, 2001. "Choosing the Number of Instruments," Econometrica, Econometric Society, vol. 69(5), pages 1161-1191, September.
  7. Alastair R. Hall & Fernanda P. M. Peixe, 2003. "A Consistent Method for the Selection of Relevant Instruments," Econometric Reviews, Taylor & Francis Journals, vol. 22(3), pages 269-287, January.
  8. Touhami Abdelkhalek & Jean-Marie Dufour, 1998. "Statistical Inference For Computable General Equilibrium Models, With Application To A Model Of The Moroccan Economy," The Review of Economics and Statistics, MIT Press, vol. 80(4), pages 520-534, November.
  9. Hall, Alastair R & Rudebusch, Glenn D & Wilcox, David W, 1996. "Judging Instrument Relevance in Instrumental Variables Estimation," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 37(2), pages 283-298, May.
  10. John Bound & David A. Jaeger & Regina Baker, 1993. "The Cure Can Be Worse than the Disease: A Cautionary Tale Regarding Instrumental Variables," NBER Technical Working Papers 0137, National Bureau of Economic Research, Inc.
  11. Davidson, Russell & MacKinnon, James G., 1993. "Estimation and Inference in Econometrics," OUP Catalogue, Oxford University Press, number 9780195060119.
  12. Zivot, Eric & Startz, Richard & Nelson, Charles R, 1998. "Valid Confidence Intervals and Inference in the Presence of Weak Instruments," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 39(4), pages 1119-1146, November.
  13. Hahn, Jinyong & Hausman, Jerry, 2002. "Notes on bias in estimators for simultaneous equation models," Economics Letters, Elsevier, vol. 75(2), pages 237-241, April.
  14. Jean-Marie Dufour & Jan F. Kiviet, 1998. "Exact Inference Methods for First-Order Autoregressive Distributed Lag Models," Econometrica, Econometric Society, vol. 66(1), pages 79-104, January.
  15. Harrison, Ann, 1996. "Openness and growth: A time-series, cross-country analysis for developing countries," Journal of Development Economics, Elsevier, vol. 48(2), pages 419-447, March.
  16. Choi, In & Phillips, Peter C. B., 1992. "Asymptotic and finite sample distribution theory for IV estimators and tests in partially identified structural equations," Journal of Econometrics, Elsevier, vol. 51(1-2), pages 113-150.
  17. Richard Startz & Charles Nelson & Eric Zivot, 1999. "Improved Inference for the Instrumental Variable Estimator," Working Papers 0039, University of Washington, Department of Economics.
  18. N. Gregory Mankiw & David Romer & David N. Weil, 1992. "A Contribution to the Empirics of Economic Growth," The Quarterly Journal of Economics, Oxford University Press, vol. 107(2), pages 407-437.
  19. Angrist, Joshua D & Krueger, Alan B, 1995. "Split-Sample Instrumental Variables Estimates of the Return to Schooling," Journal of Business & Economic Statistics, American Statistical Association, vol. 13(2), pages 225-235, April.
  20. Dufour, Jean-Marie & Jasiak, Joann, 2001. "Finite Sample Limited Information Inference Methods for Structural Equations and Models with Generated Regressors," International Economic Review, Department of Economics, University of Pennsylvania and Osaka University Institute of Social and Economic Research Association, vol. 42(3), pages 815-843, August.
  21. Jiahui Wang & Eric Zivot, 1998. "Inference on Structural Parameters in Instrumental Variables Regression with Weak Instruments," Econometrica, Econometric Society, vol. 66(6), pages 1389-1404, November.
  22. Joshua D. Angrist & Alan B. Keueger, 1991. "Does Compulsory School Attendance Affect Schooling and Earnings?," The Quarterly Journal of Economics, Oxford University Press, vol. 106(4), pages 979-1014.
  23. Cragg, John G. & Donald, Stephen G., 1993. "Testing Identifiability and Specification in Instrumental Variable Models," Econometric Theory, Cambridge University Press, vol. 9(02), pages 222-240, April.
  24. James H. Stock & Motohiro Yogo, 2002. "Testing for Weak Instruments in Linear IV Regression," NBER Technical Working Papers 0284, National Bureau of Economic Research, Inc.
  25. Douglas Staiger & James H. Stock, 1997. "Instrumental Variables Regression with Weak Instruments," Econometrica, Econometric Society, vol. 65(3), pages 557-586, May.
  26. Burnside, Craig, 1996. "Production function regressions, returns to scale, and externalities," Journal of Monetary Economics, Elsevier, vol. 37(2-3), pages 177-201, April.
  27. Stock, James H & Wright, Jonathan H & Yogo, Motohiro, 2002. "A Survey of Weak Instruments and Weak Identification in Generalized Method of Moments," Journal of Business & Economic Statistics, American Statistical Association, vol. 20(4), pages 518-529, October.
  28. Maddala, G S, 1974. "Some Small Sample Evidence on Tests of Significance in Simultaneous Equations Models," Econometrica, Econometric Society, vol. 42(5), pages 841-851, September.
  29. John Chao, 2000. "On the Bias and MSE of the IV Estimator Under Weak Identification," Econometric Society World Congress 2000 Contributed Papers 1622, Econometric Society.
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