@article{Hotz1997,
author = {Hotz, V.J. and Mullin, C.H. and Sanders, S.G.},
title= {Bounding Causal Effects Using Data from a Contaminated Natural Experiment: Analysing the Effects of Teenage Childbearing},
year = {1997},
doi = {10.2307/2971732},
journal = {The Review of Economic Studies},
volume = {64},
number = {4},
pages = {575--603},
}