César A. Hidalgo writes:
For decades, economists have been demanding non-aggregate theories of economic growth and development. Perhaps Wassily Leontief said it first when he emphasized that a true understanding of the economy needs to look “under the hood” of economic aggregates.[1] But the voice of Leontief, although no longer present, is still prevalent in his writings and that of others. Contemporaries of Leontief, such as Simon Kuznets, and more recent economists and scholars, such as Robert Lucas (1988),[2] Esther Duflo and Abhijit Banerjee (2005) — and, of course, yours truly (Hausmann and Hidalgo 2011) — have also called for an understanding of the process of economic growth and development that avoids aggregation. But why?More here