Comment

978-0-226-26034-1/2012/2011-0011$10.00 Spolare and Wacziarg (2009) construct a measure of genetic distance to proxy differences in customs, norms, and other ethnic traits. They establish a statistically signifi cant empirical relationship between genetic distance and crosscountry income differences. The current paper aims to provide a channel for this relationship through differences in adoption of technologies across countries. It estimates an empirical relationship between genetic distance and adoption of technologies across countries, where both measures are relative to a frontier country. More specifi cally, this is done by using data on genetic distance they used in their previous paper, and two data sets on technology adoption for the year 1500 and 2000. The frontier is the United Kingdom for the year 1500 and the United States for the year 2000. For the year 2000, the paper relates relative genetic distance to three layers of technology adoption: (1) 33 specifi c technologies in the CrossCountry Historical Adoption of Technology (CHAT) and 9 specifi c technologies in Comin, Easterly, and Gong (2010) (hereafter Comin et al.); (2) 4 sectors: agriculture, industry, communication, and transportation; and (3) Aggregate total factor productivity (TFP). I have two sets of comments. The fi rst concerns the data and the methodology on estimating the relationship of adoption of specifi c technologies and genetic distance. The second is about aggregating the adoption of specifi c technologies into sectoral and aggregate economy level.