Premium
Testing the Validity of the Sibling Sex Ratio Instrument
Author(s) -
Huber Martin
Publication year - 2015
Publication title -
labour
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 34
eISSN - 1467-9914
pISSN - 1121-7081
DOI - 10.1111/labr.12045
Subject(s) - instrumental variable , fertility , sibling , statistics , psychology , identification (biology) , econometrics , test (biology) , monotonic function , social psychology , mathematics , demography , developmental psychology , population , sociology , biology , paleontology , botany , mathematical analysis
We test the validity of the sibling sex ratio instrument suggested by A ngrist and E vans using the methods proposed by K itagawa and H uber and M ellace. The sex ratio of the first two siblings is arguably randomly assigned and influences the probability of having a third child, which makes it a candidate instrument for fertility when estimating the effect of fertility on female labor supply. However, identification hinges on the random assignment of the instrument, an instrumental exclusion restriction, and the monotonicity of fertility in the instrument. We find that the instrumental variable tests of K itagawa and H uber and M ellace do not point to a violation of these assumptions in the A ngrist and E vans data (which can, however, not be ruled out even asymptotically as the tests cannot detect all possible violations).