This paper builds on the work of Acemoglu et al. (2012) and considers a production network with unobserved common technological factor and establishes general conditions under which the network structure contributes to aggregate fluctuations. It introduces the notions of strongly and weakly...

"Learning-by-doing" is usually identified as a process whereby performance increases with experience in production. The paper investigates different patterns of "learning by doing", studying learning curves at product level. Cost-quantity relationships differ a lot across products belonging to...

City size distributions are known to be well approximated by power laws across many countries. One popular explanation for such power-law regularities is in terms of random growth processes, where power laws arise asymptotically from the assumption of iid growth rates among all cities within a...

This paper analyses the statistical distribution of war size. We find strong support for a Pareto-type distribution (power law) using data from different sources (COW and UCDP) and periods. A power law describesaccurately the size distribution of all wars, but also the distribution of the sample...