Prof. Dr. Stefano H. Baruffaldi

Articles in Refereed Journals

Baruffaldi, Stefano Horst; Poege, Felix (2024). Like Stars: How Firms Learn at Scientific Conferences, Management Science 2024. DOI

• Scientific conferences are an underexplored channel by which firms can learn from science. We provide empirical evidence that firms learn from scientific conferences in which they participate but also that this is conditional on intense participation. Using data from conference papers in computer science since the 1990s, we show that corporate investments in participation are both frequent and highly skewed, with some firms contributing to a given conference scientifically, some as sponsors, and some doing both. We use direct flights as an instrumental variable for the probability that other scientists participate in the same conference as a firm, altering the knowledge set to which the firm is exposed. We find that a firm’s use of scientists’ knowledge increases when they participate in the same conferences. Greater participation efforts, where the firm seeks the spotlight by both sponsoring the conference and contributing to its scientific discourse, foretell research collaborations and a stronger learning effect. Such learning is disproportionately concentrated among the most prominent firms and scientists rather than benefitting those without alternative interaction channels. Therefore, on average, firms learn from scientists that they encounter at conferences, but the substantial heterogeneity of the effect reflects the influence of reputation mechanisms in social interactions.
• Also published as: Max Planck Institute for Innovation & Competition Research Paper No. 20-10

Baruffaldi, Stefano Horst; Simeth, Markus; Wehrheim, David (2023). Asymmetric Information and R&D Disclosure: Evidence from Scientific Publications, Management Science 2023. DOI

• We examine how asymmetric information in financial markets affects voluntary research and development (R&D) disclosure, considering scientific publications as a disclosure channel. Difference-in-differences regressions around brokerage house mergers and closures, which increase information asymmetry through reductions in analyst coverage, indicate a quick and sustained increase in scientific publications from treated firms relative to the number of publications from control firms. The treatment effects are concentrated among firms with higher information asymmetry and lower investor demand, firms with greater financial constraints, and firms with lower proprietary costs. We do not find evidence of changes in financial disclosure, nor do we find changes in patenting. Results from ordinary least squares regressions show that scientific publications by firms are positively associated with investor attention toward those firms. We complement these results with qualitative evidence from conference calls. Our results highlight the limitations and trade-offs R&D firms face in their financial market disclosure policies.
• Also published in SSRN

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

Ganguli, Ina; Rose, Michael; Ivashchenko, Oleksandra; Baruffaldi, Stefano Horst (2023). Ukrainian Science is Struggling, Threatening Long-Term Economic Recovery – History Shows Ways to Support the Ukrainian Scientific System, The Conversation 2023.

• https://theconversation.com/ukrainian-science-is-struggling-threatening-long-term-economic-recovery-history-shows-ways-to-support-the-ukrainian-scientific-system-207477

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.

• Article "Science Quality and the Value of Inventions" in Science Advances, Vol. 5 (2019) No. 12, eaay7323
• More detailed online version of the article in Research Europe, which was the basis for the printed article.

Discussion Papers

Baruffaldi, Stefano Horst; Simeth, Markus; Wehrheim, David (2023). Asymmetric Information and R&D Disclosure: Evidence from Scientific Publications. DOI

• We examine how asymmetric information in financial markets affects voluntary R&D disclosure, considering scientific publications as a disclosure channel. Difference-in-differences regressions around brokerage house mergers and closures, which increase information asymmetry through reductions in analyst coverage, indicate a quick and sustained increase in scientific publications from treated firms relative to the number of publications from control firms. The treatment effects are concentrated among firms with higher information asymmetry and lower investor demand, firms with greater financial constraints, and firms with lower proprietary costs. We do not find evidence of changes in financial disclosure, nor do we find changes in patenting. Results from ordinary least squares regressions show that scientific publications by firms are positively associated with investor attention toward those firms. We complement these results with qualitative evidence from conference calls. Our results highlight the limitations and trade-offs R&D firms face in their financial market disclosure policies.
• Forthcoming in Management Science

Baruffaldi, Stefano Horst; Poege, Felix (2022). Like Stars: How Firms Learn at Scientific Conferences, Max Planck Institute for Innovation & Competition Research Paper, No. 20-10. DOI

• Scientific conferences are an underexplored channel by which firms learn from science. Although attendance per se may be sufficient to lower search costs in relation to scientific knowledge, we show that active participation and corporate investments in reputation are necessary to establish the personal connections that act as the key learning channel. Using data from conference papers in computer science since the 1990s, we show that corporate investments in participation are both frequent and highly skewed, some firms contributing to a given conference scientifically, some as sponsors, and some doing both. We use direct flights as an instrumental variable for the probability that other scientists participate in the same conference as a firm and find that this increases the firm’s use of the scientists’ knowledge. However, the most significant benefits accrue if the firm seeks the spotlight by both sponsoring the conference and taking part in its scientific discourse. Additional analyses show that these efforts foretell research collaborations and suggest that participation is more relevant in circumstances where the conference helps to trigger personal interactions, even when knowledge search costs are otherwise low.
• Forthcoming in: Management Science

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.