The majority of immigrants stay only temporarily in the host country. When many migrations are temporary, it is important to know who leaves and who stays, and why. The key questions for the host country are whether immigrants are net contributors to the welfare system and whether migrants...

Abstract Ridder and Woutersen (Ridder, G., and T. Woutersen. 2003. “The Singularity of the Efficiency Bound of the Mixed Proportional Hazard Model.” Econometrica 71: 1579–1589) have shown that under a weak condition on the baseline hazard, there exist root-N consistent estimators of the...