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Source: Thomas Jefferson Center for Political Economy Working Paper Series
Resulting in 1 citation.
1. Manski, Charles F.
Pepper, John V.
Monotone Instrumental Variables: with an Application to the Returns to Schooling
Working Paper 308, Thomas Jefferson Center for Political Economy Working Paper Series, University of Virginia, January 1998
Cohort(s): NLSY79
Publisher: Department of Economics, University of Virginia
Keyword(s): Armed Forces Qualifications Test (AFQT); Educational Returns; Schooling; Treatment Response: Monotone, Semimonotone, or Concave-monotone; Variables, Independent - Covariate; Variables, Instrumental

Permission to reprint the abstract has not been received from the publisher.

Econometric analyses of treatment response commonly use instrumental variable (IV) assumptions to identify treatment effects. Yet the credibility of IV assumptions is often a matter of considerable disagreement, with much debate about whether some covariate is or is not a "valid instrument" in an application of interest. There is therefore good reason to consider weaker but more credible assumptions. To this end, we introduce monotone instrumental variable (MIV) assumptions. A particularly interesting special case of an MIV assumption is monotone treatment selection (MTS). IV and MIV assumptions may be imposed alone or in combination with other assumptions. We study the identifying power of MIV assumptions in three informational settings: MIV alone; MIV combined with the classical linear response assumption; MIV combined with the monotone treatment response (MTR) assumption. We apply the results to the problem of inference on the returns to schooling. We analyze wage data reported by white male respondents to the National Longitudinal Survey of Youth (NLSY) and use the respondent's AFQT score as an MIV. We find that this MIV assumption has little identifying power when imposed alone. However combining the MIV assumption with the MTR and MTS assumptions yields fairly tight bounds on two distinct measures of the returns to schooling.
Bibliography Citation
Manski, Charles F. and John V. Pepper. "Monotone Instrumental Variables: with an Application to the Returns to Schooling." Working Paper 308, Thomas Jefferson Center for Political Economy Working Paper Series, University of Virginia, January 1998.