An employment study by Mincer illustrated that earning differentials are directly correlated with the cognitive skills; number of years of schooling, and the number of training sessions they have successfully completed(Mincer, 1958: 281 302). Later, some studies recognized that both cognitive and noncognitive skills are strong forecasters determining schooling attainment and wages. Noncognitive skills affect level of earnings as a latent influence to cognitive abilities (Heckman, Stixrud and Urzua, 2006: 134; Weel, 2008: 729737). Therefore, ...