Input-output analysis and growth theory

This thesis studies a theory for the amplification of technological improvement by the production network structure of the economy. The theory is motivated by the idea that, to the extent that inputs and outputs of industries form a chain, improvements are passed down the chain and accumulate multiplicatively. Under a simple model for technological improvement it is possible to compute the overall improvement factor for the general case where the production network has a complicated structure containing cycles. We call this the trophic depth by analogy with ecology. This leads to testable predictions about GDP growth and its variance. We analyse data for 40 countries and 35 industries from 1995 to 2009 and demonstrate that trophic depths are strongly correlated with economic growth. A regression of GDP growth of countries against their trophic depths has a highly statistically significant R-squared equal to 0.38, and when other standard explanatory variables are added to the regression, the trophic depth remains a robust and statistically significant contributor. We perform some statistical analysis to understand the evolution of trophic depths at different stage of the economic development. We identify two growth paths. Along the first growth path, countries are catching up frontier economies while along the second growth path countries are falling behind. This approach allows us to make some forecasts about the evolution of trophic depths and of the wealth of countries. This provides a comprehensive framework to understand the acceleration and deceleration of economic growth. Then, we study another type of technological progress that corresponds to the adoption of new goods in the production chain. This mechanism is related to the dynamic of the production network and for this purpose we perform a link prediction analysis to determine some key factors for new adoptions. Finally, we analyse the relation between stock return comovement and institutional preferences across stocks of various size. A growing literature highlights the role of investors' common asset holdings on market dynamics. While previous studies focused on large stocks we also include small stocks in the sample in order to acknowledge the shift in institutional preferences towards small stocks over the last decades. Moreover, we add the input-output linkages between firms from different industries to our set of explanatory variables.