Aid and Income: Another Time-series Perspective

This study provides a replication of the empirical results reported by Nowak-Lehmann, Dreher, Herzer, Klasen, and Martínez-Zarzoso (2012) (henceforth NDHKM). We uncover that NDHKM relied on a regression model which included a log transformation of variables that are not strictly positive. This led to nonrandom omission of a large proportion of observations. Furthermore, we show that NDHKM’s use of co-integrated regressions is not a suitable empirical strategy for estimating the causal effect of aid on income. Evidence from a Panel VAR model estimated on the dataset of NDHKM, suggests a positive and statistically significant long-run effect of aid on income.