Pier Paolo Creanza

Publications

Institutions, trade and growth: the ancient Greek case of proxenia [Paper] [Replication kit] - Journal of Economic History, Volume 84, Issue 1 (Lead Article)

Recent scholarship contends that ancient Mediterranean economies grew intensively. An explanation is Smithian growth spurred by reductions in transaction costs and increased trade flows. This paper argues that an ancient Greek institution, proxenia, was among the innovations that allowed such growth in the period 500-0 BCE. Proxenia entailed a Greek city-state declaring a foreigner to be its ‘public friend’, a status that conferred both duties and privileges. Arguably, the functions performed by ‘public friends’ could facilitate economic transactions between communities. Accordingly, network and regression analyses establish a strong relation between proxenia grants and trade intensity.

Working papers

Factories of Ideas? Big Business and the Golden Age of American Innovation (JMP) - Draft available in the fall

This paper examines how the rise of Big Business transformed American innovation between 1880 and 1940. Using the Great Merger Wave of 1895-1904 as a quasi-experiment, I establish the causal relationship between industrial consolidation and innovation through newly constructed firm-level data. On the intensive margin, firms that underwent mergers experienced a substantial increase in patenting and breakthrough innovations. On the extensive margin, consolidations had a significantly higher likelihood to begin patenting. On both margins, consolidated firms were also much more likely to establish R&D laboratories. At the aggregate level, I find no evidence of negative spillovers on other firms or inventors in technologies more exposed to the consolidation wave. In fact, breakthrough innovation in more science-based technologies benefited. A crucial mechanism behind these changes was the establishment of corporate R&D laboratories, which systematized the discovery process and accounted for substantial firm-level innovation gains. These results provide new quantitative evidence that the rise of Big Business  before World War II had significant and lasting effects on the trajectory of American innovation.

'Returning brains':  tax incentives, migration, and scientific productivity

This paper investigates how tax incentives for high-skill immigrants affect productivity. I collect data covering 90 percent of Italian faculty between 2000 and 2020 and use it to evaluate a 2004 tax break targeting researchers. First, the program induced substantial migration and positive selection of beneficiaries. Second, higher-productivity hires significantly increase their academic group's average productivity, roughly split between their direct contribution and indirect responses of local faculty. Third, this indirect effect is largely explained by higher-productivity local researchers sorting into the treated group, rather than by productivity spillovers on incumbent researchers.

Work in progress

The changing spatial concentration of innovative activity
- with Pietro Buri

The Red Scare and racial inequality
- with Leah Boustan, Ilyana Kuziemko and Suresh Naidu