Using a large, individual-level wage data set, we examine the impact of a major technological innovation—the steam engine—on the demand for skills in the merchant shipping industry. We find that the technical change created a new demand for engineers, a skilled occupation. It had a deskilling effect on production work—moderately skilled able-bodied seamen were replaced by unskilled engine room operatives. On the other hand, able-bodied seamen, carpenters, and mates employed on steam vessels earned a premium relative to their counterparts on sail vessels, and this appears partly related to skill.

I report new evidence for localized knowledge spillovers identified by within-patent variations in the geographic matching rates of citations added by inventors and citations added by examiners. Evaluated at the mean citation lag, inventor citations are 20% more likely than examiner citations to match the country of origin of their citing patent, whereas U.S. inventor citations are 25% more likely to match the state or metropolitan area of their citing patent. The localization of intranational knowledge spillovers declines with the passage of time, but international borders present a persistent barrier to spillovers.

Several theories of firm performance can explain the well known observation that survival is positively related to age. However, a more mundane explanation—selection bias driven by variations in firm quality—may also underlie the phenomenon. This paper employs a 90 year plant-level panel data set on the U.S. iron and steel shipbuilding industry of the nineteenth and early twentieth centuries to discriminate between the explanations. The shipbuilding industry exhibits the usual joint dependence of survival on age and size, but this dependence is eliminated after controlling for heterogeneity by using preentry experience as a proxy for firm quality. The evidence points to a dominant role for selection bias in creating the age dependence of survival. At the same time, preentry experience is found to have a large and extremely persistent effect on survival, and this finding is inconsistent with standard explanations for the role of preentry experience on firm performance.