"One of the most complex and empirically unsettled subjects in economics is the explanation of the process of economic growth. As the creation of wealth is of critical importance for the welfare of most people around the world the current disarray in growth economics is not only a topic of analytical interest but also of practical importance. One of the controversies in growth analysis is the relative role of capital accumulation and productivity growth in driving output" (Gutierrez and Solimano, 2007, p.1).