Introduction to Modern Economic Growth College wage premium Rel supply of college skills 4 39 49 59 69 year 79 89 96 Relative Supply of College Skills and College Premium Figure 15.1 Relative supply of college graduates and the college premium in the U.S labor market happy to treat the bias of technological change as exogenous, this is not entirely satisfactory We have seen that understanding the endogenous nature of technology is important for our study of cross-country income differences and the process of modern economic growth It is unlikely that, while the amount of aggregate technological change is endogenous, the bias of technological change is entirely exogenous It is therefore important to study the determinants of endogenous bias of technological change and ask why technological change has become more skill biased in recent decades (2) This conclusion is strengthened when we look at the historical process of technological change In contrast to the developments during the recent decades, technological changes during the late 18th and early 19th centuries 657 Rel supply of college skills College wage premium