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Testing for Nonparametric Identification of Causal Effects in the Presence of a Quasi-Instrument
de Luna, Xavier; Johansson, Per - Institute for the Study of Labor (IZA) - 2012
The identification of average causal effects of a treatment in observational studies is typically based either on the unconfoundedness assumption or on the availability of an instrument. When available, instruments may also be used to test for the unconfoundedness assumption (exogeneity of the...
Persistent link: https://www.econbiz.de/10010990937
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Heterogeneous Treatment Effects: Instrumental Variables without Monotonicity?
Klein, Tobias J. - Institute for the Study of Labor (IZA) - 2007
treatment decision depend on each other. Imbens and Angrist (1994) were the first to exploit a monotonicity condition in order …, identification hinges on the same monotonicity assumption that is fundamentally untestable. We investigate the sensitivity of … respective estimates to reasonable departures from monotonicity that are likely to be encountered in practice and relate it to …
Persistent link: https://www.econbiz.de/10005822349