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An R implementation of the Necessary and Probably Sufficient (NPS) test for finding valid instrumental variables, as suggested by Amit Sharma (2016, Working Paper) <http://amitsharma.in/pubs/necessary_probably_sufficient_iv_test.pdf>. The NPS test, compares the likelihood that a given set of observational data of the three variables Z, X and Y is generated by a valid instrumental variable model (Z > X > Y) to the likelihood that the data is generated by an invalid IV model.
Package details 


Author  Fabian Sellmann [aut, cre], Bojan Nicolic [ctb, cph], Jörn Grahl [ths] 
Maintainer  Fabian Sellmann <fa.sllmnn@gmail.com> 
License  GPL2 
Version  0.1.1 
Package repository  View on CRAN 
Installation 
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