Dr. Stefano H. Baruffaldi

Affiliated Research Fellow

Innovation and Entrepreneurship Research
Assistant Professor, University of Bath

stefano.baruffaldi(at)ip.mpg.de

Areas of Interest:

Economics of Innovation, Economics of Science, Geography of Innovation, Knowledge Diffusion, International Mobility of Researchers, Innovation and Inequality

Academic Résumé

Since 01/2019
Assistant Professor at the University of Bath

Affiliated Research Fellow at the Max Planck Institute for Innovation and Competition (Innovation and Entrepreneurship Research)

03/2018 - 01/2019
Senior Research Fellow at the Max Planck Institute for Innovation and Competition (Innovation and Entrepreneurship Research)

08/2016 - 02/2018
Affiliated Research Fellow at the Max Planck Institute for Innovation and Competition (Innovation and Entrepreneurship Research)

07/2015 - 07/2016
Young Economics/Policy Analyst at the OECD

09/2010 - 06/2015
PhD Candidate and Teaching Assistant at the Ecole Polytechnique Fédérale de Lausanne (EPFL). Doctoral Thesis: Three Essays on the Role of Proximity in Science and Innovation

09/2004 - 03/2010
Bachelor of Science and Master of Science in Engingeering and Industrial Management at the Politecnico di Milano

Publications

Articles in Refereed Journals

Baruffaldi, Stefano Horst; Marino, Marianna; Visentin, Fabiana (2020). Money to Move: The Effect on Researchers of an International Mobility Grant, Research Policy, 49 (8). DOI

  • We examine the impact of a grant program promoting international mobility on researchers’ scientific outcomes and careers. To provide causal evidence, we exploit unique data from the Swiss National Foundation and implement a Regression Discontinuity Design analysis. We find that the grant effectively supports periods of research abroad that often extend beyond the duration of the grant, without increasing the probability of permanent migration. Awarded researchers increase their output quality, although the effect on output quantity and careers is not significant. Additional evidence suggests that financing international mobility likely affects output quality by reducing the cost of exploring new collaboration opportunities and research topics: awarded applicants are more likely to collaborate with new coauthors of higher, on average, scientific quality and rely less on their previous own research results. Moreover, the grants mainly benefit researchers receiving a mobility grant for the first time.

Baruffaldi, Stefano Horst; Byrski, Dennis; Gaessler, Fabian (2020). Fire and Mice: The Effect of Supply Shocks on Basic Science, Academy of Management Proceedings, 2020 (1). DOI

  • We study how a negative supply shock to research-related assets affects the production of scientific knowledge. In particular, we exploit the 1989 Morrell Park fire that destroyed a considerable share of the world's largest mice breeding facility, the Jackson Laboratory, and killed approximately 400,000 mice. This fire led to an unforeseen and substantial supply shortage in mice for the North American biomedical research community, which we can isolate at the strain and scientist level based on proprietary archival data. Using difference-in-differences estimations, we find that the scientific productivity of affected scientists decreases when measured in simple publication counts, but much less so when we adjust for the publications' quality. Moreover, affected researchers are more likely to initiate research that is unrelated to their previous work. This indicates that affected scientists switched research trajectories but maintained their scientific impact. In the aggregate, the temporary supply shortage of particular mice strains led to a permanent decrease in their usage among U.S.\ scientists. These results highlight the important role of supply chains in basic science."

Baruffaldi, Stefano Horst; Simeth, Markus (2020). Patents and Knowledge Diffusion: The Effect of Early Disclosure, Research Policy, 49 (4). DOI

  • We study how the timing of information disclosure affects the diffusion of codified technical information. On November 29, 2000, the American Inventors Protection Act (AIPA) reduced the default publication time of patents at the United States Patent and Trademark Office (USPTO) to 18 months. We analyze the effects of this change by means of a regression discontinuity design with time as an assignment variable and a complementary difference-in-differences analysis. Our study shows that information flows from patents measured by forward citations, increased. Interestingly, the degree of localization within geographic boundaries remained unchanged and technological localization even increased moderately. Moreover, the effect of early disclosure on citations from patents filed by patent attorney service firms is particularly strong. These results imply that knowledge diffusion stemming from speedier disclosure of technical information is confined to the existing attention scope and absorptive capacity of inventors and organizations.

Poege, Felix; Harhoff, Dietmar; Gaessler, Fabian; Baruffaldi, Stefano Horst (2019). Science Quality and the Value of Inventions, Science Advances, 5 (12), eaay7323. DOI

  • Despite decades of research, the relationship between the quality of science and the value of inventions has remained unclear. We present the result of a large-scale matching exercise between 4.8 million patent families and 43 million publication records. We find a strong positive relationship between quality of scientific contributions referenced in patents and the value of the respective inventions. We rank patents by the quality of the science they are linked to. Strikingly, high-rank patents are twice as valuable as low-rank patents, which in turn are about as valuable as patents without direct science link. We show this core result for various science quality and patent value measures. The effect of science quality on patent value remains relevant even when science is linked indirectly through other patents. Our findings imply that what is considered “excellent” within the science sector also leads to outstanding outcomes in the technological or commercial realm.
  • Also published as: arXiv preprint 1903.05020
  • Article: Excellence Breeds Invention, Research Europe 510 (2020), 11

Baruffaldi, Stefano Horst; Marino, Marianna; Visentin, Fabiana (2017). International Mobility and Research Careers: Evidence from a Mobility Grant Program, Academy of Management Proceedings, 2017 (1), 2017 (1)28. DOI

  • Despite the acknowledged importance of international mobility for science and innovation, there is limited evidence on the effect on researchers of incentives and programs to support it. In this paper we estimate the impact of an international mobility grant program on the careers of 946 researchers in Switzerland. Data from the Swiss National Foundation (SNSF) allow us to implement a Regression Discontinuity Design regression analysis to assess the causal effect of the program on a series of outcomes of interest. Looking at the years that follow the proposed starting year of the grant, awarded applicants result 54% more likely to be abroad in the first year than not awarded applicants. The effect of the grant extends beyond the period founded by the grant it-self. However, in line with the program objectives, return appears likely since this effect is reduced to 18% and is weakly significant on the fifth year. Over the same period, we find no significant effect on scientific productivity, when measured as number of publications, and a weakly significant negative effect, when measured as total number of citations. Similarly, we find no effect on the likelihood of obtaining a professorship position. On the contrary, we find a positive significant effect on the number of new co-authors. We discuss the implications of these results for the understanding of the effects of international mobility and for organizations that intend to support it.

Baruffaldi, Stefano Horst; Raffo, Julio (2017). The Geography of Duplicated Inventions: Evidence from Patent Citations, Regional Studies, 51 (8), 1232-1245. DOI

  • The geography of duplicated inventions: evidence from patent citations. Regional Studies. Innovators often claim inventions that turn out to duplicate, at least in part, existing ones. This paper advances the claim that for recent and upcoming inventions, competitive incentives are high, and localized knowledge flows increase the probability of duplication. Therefore, over a brief period of time the probability of duplication is higher at short geographical distance. Conversely, the duplication of less recent inventions is more likely at long distance as a consequence of a lower awareness of the existence of a technology. This claim is supported by coherent descriptive and multivariate evidence using data on patent citation categories from the European Patent Office (EPO).

Baruffaldi, Stefano Horst; Di Maio, Giorgio; Landoni, Paolo (2017). Determinants of PhD Holders’ Use of Social Networking Sites: An Analysis Based on LinkedIn, Research Policy, 46 (4), 740-750. DOI

    Baruffaldi, Stefano Horst; Marino, Marianna; Parrotta, Pierpaolo (2016). Self-employment, Start-up Incentives and Political Ideology, Applied Economics Letters, 23 (4), 250-254.

      Baruffaldi, Stefano Horst; Visentin, Fabiana; Conti, Annamaria (2016). The Productivity of Science & Engineering PhD Students Hired from Supervisors’ Networks, Research Policy, 45 (4), 785-796. DOI

      • We compare the scientific productivity of PhD students who are hired from a fine-grained set of mutually exclusive affiliation types: a PhD supervisor's affiliation, an external affiliation from which the supervisor derives her coauthors, and an external affiliation with which the supervisor has no coauthorship ties. Using a novel dataset of science and engineering PhD students who graduated from two major Swiss universities, we find that the most productive PhD category is the one made of students who are affiliated with universities other than their supervisors’ affiliation, but from which the PhD supervisors derive their coauthors. This result suggests an inverted U-shaped relationship between PhD students’ productivity and the social distance from their supervisors. Additionally, we find evidence consistent with the role of supervisors’ coauthor networks in resolving information asymmetries regarding PhD talent.

      Baruffaldi, Stefano Horst; Landoni, Paolo (2016). Mobility Intentions of Foreign Researchers: The Role of Non-economic Motivations, Industry and Innovation, 23 (1), 87-111.

      • Recent contributions suggest that non-economic factors could be important motivational drivers of scientific mobility. We investigate this hypothesis in a sample of foreign researchers in Italy and Portugal, examining their willingness to leave the host country. We distinguish between economic factors, non-economic relational factors and non-economic aspirational factors. Controlling for the relevant contextual variables, we find that foreign researchers, unsatisfied with aspirational factors (e.g. level of independence, autonomy, intellectual challenge and social status), are more likely to leave their host country and move to a third country than they are to return to their countries of origin. Relational and economic factors, such as salary and benefits, do not demonstrate any additional impact.

      Further Publications, Press Articles, Interviews

      Poege, Felix; Harhoff, Dietmar; Gaessler, Fabian; Baruffaldi, Stefano Horst (2020). Excellence Breeds Invention. The Most Highly Cited Papers Feature in the Most Valuable Patents, Research Europe, (510), 11.

      Discussion Papers

      Baruffaldi, Stefano Horst; Gaessler, Fabian (2021). The Returns to Physical Capital in Knowledge Production: Evidence from Lab Disasters, Max Planck Institute for Innovation & Competition Research Paper, No. 21-19. DOI

      • We establish the importance of physical capital in knowledge production. To this end, we exploit adverse events (explosions, fires, floods, etc.) at research institutions as exogenous physical capital shocks. Scientists experience a substantial and persistent reduction in research output if they lose specialized physical capital, that is, equipment and material they created over time for a particular research purpose. In contrast, they quickly recover if they only lose generic physical capital. Affected scientists in older laboratories, which presumably lose more obsolete physical capital, are more likely to change their direction of research and recover in scientific productivity. These findings suggest that a scientist's investments into their own physical capital yield lasting returns but also create path dependence in relation to research direction.

      Rose, Michael; Baruffaldi, Stefano Horst (2020). Finding Doppelgängers in Scopus: How to Build Scientists Control Groups Using Sosia, Max Planck Institute for Innovation & Competition Research Paper, No. 20-20. DOI

      • The construction of control groups of scientists is often a daunting effort. This paper presents sosia, an open-source Python-based software designed to query efficiently the Scopus database via RESTful API. sosia searches for researchers with publication profiles similar to a given researcher up to a given year based on all main standard bibliometric indicators. The user can choose flexibly a set of parameters to restrict the search to more or less narrow boundaries upfront and obtain additional similarity indicators to select a subset of authors after the search. Advanced settings also allow to narrow the search to a list of affiliations and to minimize the possible errors arising from ambiguous author profiles. One basic search can be set up in a few command lines and the average time of computation goes between 60 and 300 minutes. We discuss the functioning, characteristics, limitations and possible extension of the software.

      Baruffaldi, Stefano Horst; Poege, Felix (2020). A Firm Scientific Community: Industry Participation and Knowledge Diffusion, IZA Discussion Paper, No. 13419.

      • We study the diffusion of knowledge from scientists to firms within scientific communities. We build on a unique dataset on conference proceedings as "paper trail" of almost all relevant conference series in computer science since 1996. More than 5000 firms appear as conference sponsors or as affiliations in proceedings. Their participation is concentrated in the highly ranked conferences and their scientific contributions are on average highly cited. We exploit direct flights as an instrumental variable for the participation choice of scientists between a conference where a firm participates and other similar conferences. The participation in the same conference has a positive causal effect on knowledge diffusion to the firm's scientific and inventive activities. Additional analyses suggest that interactions and collaborations with scientists that remain external to the firm are likely a key mechanism of this diffusion. The effects are remarkably stronger the larger the firm's investments in participation.
      • https://www.iza.org/de/publications/dp/13419/a-firm-scientific-community-industry-participation-and-knowledge-diffusion

      Baruffaldi, Stefano Horst; Poege, Felix (2020). A Firm Scientific Community: Industry Participation and Knowledge Diffusion, Max Planck Institute for Innovation & Competition Research Paper, No. 20-10.

      • We study the diffusion of knowledge from scientists to firms within scientific communities. We build on a unique dataset on conference proceedings as “paper trail” of almost all relevant conference series in computer science since 1996. More than 5000 firms appear as conference sponsors or as affiliations in proceedings. Their participation is concentrated in the highly ranked conferences and their scientific contributions are on average highly cited. We exploit direct flights as an instrumental variable for the participation choice of scientists between a conference where a firm participates and other similar conferences. The participation in the same conference has a positive causal effect on knowledge diffusion to the firm’s scientific and inventive activities. Additional analyses suggest that interactions and collaborations with scientists that remain external to the firm are likely a key mechanism of this diffusion. The effects are remarkably stronger the larger the firm’s investments in participation.
      • Available at SSRN
      • Also published as: DRUID19; 4936

      Baruffaldi, Stefano Horst; van Beuzekom, Brigitte; Dernis, Hélène; Harhoff, Dietmar; Rao, Nandan; Rosenfeld, David; Squicciarini, Mariagrazia (2020). Identifying and Measuring Developments in Artificial Intelligence: Making the Impossible Possible, OECD Science, Technology and Industry Working Papers, No. 2020/05. DOI

      • This paper identifies and measures developments in science, algorithms and technologies related to artificial intelligence (AI). Using information from scientific publications, open source software (OSS) and patents, it finds a marked increase in AI-related developments over recent years. Since 2015, AI-related publications have increased by 23% per year; from 2014 to 2018, AI-related OSS contributions grew at a rate three times greater than other OSS contributions; and AI-related inventions comprised, on average, more than 2.3% of IP5 patent families in 2017. China’s growing role in the AI space also emerges. The analysis relies on a three-pronged approach based on established bibliometric and patent-based methods, and machine learning (ML) implemented on purposely collected OSS data.

      Poege, Felix; Harhoff, Dietmar; Gaessler, Fabian; Baruffaldi, Stefano Horst (2019). Science Quality and the Value of Inventions, arXiv preprint 1903.05020.

      • Despite decades of research, the relationship between the quality of science and the value of inventions has remained unclear. We present the result of a large-scale matching exercise between 4.8 million patent families and 43 million publication records. We find a strong positive relationship between quality of scientific contributions referenced in patents and the value of the respective inventions. We rank patents by the quality of the science they are linked to. Strikingly, high-rank patents are twice as valuable as low-rank patents, which in turn are about as valuable as patents without direct science link. We show this core result for various science quality and patent value measures. The effect of science quality on patent value remains relevant even when science is linked indirectly through other patents. Our findings imply that what is considered “excellent” within the science sector also leads to outstanding outcomes in the technological or commercial realm.
      • https://arxiv.org/pdf/1903.05020.pdf
      • Also published in Science Advances 2019, Vol. 5, No. 12, eaay7323

      Baruffaldi, Stefano Horst; Poege, Felix (2019). A Firm Scientific Community, DRUID19, 4936. Copenhagen: Copenhagen Business School.

      • The diffusion of scientific knowledge to industry is instrumental to technological change and productivity growth. In this paper, we investigate the extent to which firms participate in scientific communities' activities and whether this facilitates the exchange and transfer of scientific knowledge to firms' technological activities. We focus on two modes of interactions of firms with scientific communities: the participation to and the sponsorship of international scientific conferences. We exploit a newly constructed database comprising the set of all conference proceedings in computer science from 1996 until 2015 from a specialized computer science database (DBLP) matched to Web of Science and Scopus and conference ranking information. We track knowledge transfers by patent and science citations to these proceedings. First, we document that both conference participation and sponsorship by firms is frequent and concentrated in the events of the highest quality. Contributions of firms at conferences are of higher average quality, even within individual conferences. Second, we go on to find that firms are significantly more likely to cite in their patents and papers the scientific articles presented at a conference which they attended relative to comparable articles presented at other conferences. We use airline connectivity between researcher and conference locations in an instrumental variable strategy to establish causality.
      • https://conference.druid.dk/acc_papers/45ci2gtnh996gaar52h23n4wfg5wfn.pdf

      Presentations and Lectures

      08.08.2020
      Fire and Mice: The Effect of Supply Shocks on Basic Science
      AOM Annual Meeting
      Location: online 


      03.03.2020
      A Firm Scientific Community: The Struggle for the Second Part of the Title
      Research Seminar
      Location: Zugspitze


      09.11.2019
      A Firm Scientific Community: Industry Participation to Academia and Knowledge Diffusion
      REER Conference
      Location: Atlanta, US


      09.08.2019
      The Geography of Duplicated Inventions: Evidence from Patent Citations
      Academy of Management Conference
      Location: Boston, US


      19.05.2019
      A Firm Scientific Community
      DRUID Conference
      Location: Copenhagen, Denmark


      16.05.2019
      Knowledge Lost in Capital
      Innopat Conference
      Location: Mannheim


      10.05.2019
      Knowledge Lost in Capital
      13th Workshop on the Organisation, Economics and Policy of Scientific Research
      Location: Bordeaux, France


      10.08.2018
      Knowledge Lost in Capital
      Academy of Management Annual Meeting
      Location: Chicago, US


      12.06.2018
      Knowledge Lost in Capital
      DRUID Conference
      Location: Copenhagen, Denmark

      Projects