Follow the Money: Online Piracy and Self-Regulation in the Advertising Industry
(joint with J Claussen and C Peukert)
International Journal of Industrial Organization, Forthcoming


We study the effects of a self-regulation effort, orchestrated by the European Commission in 2016 and finalized in 2018, that aims to reduce advertising revenues for publishers of copyright infringing content. Data on the third-party HTTP requests made by a large number of piracy websites lets us observe the relations of the piracy and advertising industry over time. We compare these dynamics to a control group of non-advertising services which are not subject to the self-regulation. Our results suggest that the effort is limited in its effectiveness. On average, the number of piracy websites that make requests to EU-based advertising services does not change significantly. Only when we allow for heterogeneity in the popularity of third-party services, we find that the number of piracy websites that interact with the most popular EU-based advertising services decreases by 42%. We do not find evidence that non-EU-based advertising services react to the self-regulation. This implies that only a small share of the firms in the market comply with self-regulation in a way that is visible in our data. We also do not find evidence that the demand for piracy websites decreases due to this “follow the money” initiative.

Working Papers

Entrepreneurs on the Darknet: Reaction to Negative Feedback
(joint with T Kretschmer)


Reputation is one of the key assets of a digital entrepreneur in markets for experience goods, especially in settings like Darknet and anonymous marketplaces. But what happens if this asset is diminished by a shock, i.e. negative feedback? We study how entrepreneurs on anonymous marketplaces respond to negative feedback by adjusting their product portfolio, or even exiting the market altogether. We find that the entrepreneurs are more likely to exit following negative feedback, but that a entrepreneur’s accumulated transactions experience on the market platform negatively moderates this. Interestingly, the entrepreneurs that do remain tend to expand their product portfolio. This effect, however, is again driven by entrepreneurs with relative high transactions experience, i.e. those with a high prior transactions volume. These results suggest that the reputation and the transactions experience of an entrepreneur interact in intricate ways to drive an entrepreneur’s choice of remaining in the market or adjusting her portfolio. We derive managerial and policy implications of these results.

The impact of demand on market entry: Evidence from Airbnb
(joint with R Breitner and J Claussen)


A key promise of the sharing economy is that peer-to-peer markets are much more flexible than traditional markets when it comes to expanding capacity. This flexibility stems from sharing platforms utilizing existing resources instead of necessitating the acquisition of new resources. We study the effect of demand on market entry for the example of Airbnb in Europe. Our results indicate that demand has a positive effect on entry, especially in cities with high housing costs. Moreover, we find that the offerings of high demand entrants tend to be of lower attractiveness. Our work provides empirical evidence that especially the entry of low-end offerings increases when demand is higher in peer-to-peer markets. These results indicate that with an increase in demand, new potential suppliers expect to have a higher chance to compete in the market, get a share of the overall revenue and thus decide to enter the market.

The Lives of Others: Impact of Formal and Informal Monitoring of the Short-term Rental Market in Barcelona
(joint with J Claussen and T Kretschmer)


The explosive growth of the sharing economy platforms (like Airbnb, Uber, etc) has heated the debate around the positive and negative ex- ternalities of these platforms. The positive externalities include the decrease of transactions and information costs, the better coordina- tion of supply and demand and the flexibility for users among others. On the hand, the negative externalities include precarious working conditions, traffic jam congestions, etc. Specifically, for the case of short-term rental platforms, citizens of highly touristic cities are heav- ily complaining about the increase of the long-term rental prices, the decrease of their quality of living (due to noise for example) and the gentrification that changes the nature of their neighbourhoods. Cities like Amsterdam, Paris, Berlin, and Barcelona have taken measures in order to minimise the network externalities of the short-term rental platforms. These measures include restrictions on the total amount of days an apartment can be rented during a year in the short-term rental market, or banning totally the offering of whole apartments. In the case of Barcelona, a special license since 2012 is needed to offer a whole apartment on a short-term rental platform like Airbnb. In July 2015, the newly elected local government led by an ex-activist against evictions, imposed a moratorium on the licenses, prohibiting the is- suing of new licenses for all tourist accommodation establishments so as to study, and in addition control, the growth of the short-term rental market. The moratorium was in force until March 2017 when a new regulation was introduced. The 2015 moratorium on licenses was accompanied with an enforcement mechanism, that included specific fines for the ones that rented their apartments illegally, the creation of a team of inspectors that are monitoring the illegal tourist accommo- dation activities and the implementation of a webpage through which Barcelonas citizens and visitors could report an illegally rented apart- ment. In this study, we try to measure the impact and effectiveness of those two monitoring processes, the formal one and the informal (crowdsourced) one. By implementing a diff-in-diff analysis, we first find a general negative impact of the moratorium on the supply of apartments in the Airbnb platform. Additionally, we find that the formal monitoring process affected mostly the professional hosts while the informal monitoring affected mostly the amateur ones.


  • Annual Meeting of Academy of Management 2018 (“Entrepreneurship in Anonymous Marketplaces: Reaction to Negative Feedback”)
  • TIME Seminar 2018 (“The Lives of Others: Impact of Formal and Informal Monitoring of the Short-term Rental Market in Barcelona”)
  • Munich Summer Institute 2018 (“Entrepreneurship in Anonymous Marketplaces: Reaction to Negative Feedback”)
  • AOM Specialized Conference: Big Data and Managing in a Digital Economy 2018 (“Advanced Techniques for Web-Scraping”)
  • ORG Seminar 2018 (“The impact of demand on supplier entry: Evidence from Airbnb”)
  • Workshop on Economic Governance of Data-driven Markets, Tilburg University 2017 (“Follow The Money: Piracy and Online Advertising”)
  • ITS-Europe Regional Conference 2017 (“Follow The Money: Piracy and Online Advertising”)
  • TIME Seminar 2017 (“Follow The Money: Piracy and Online Advertising”)
  • ORG Seminar 2017 (“Follow The Money: Piracy and Online Advertising”)
  • European Academy of Management Conference 2011 (“Participation of Catalan SMEs in FLOSS communities”)
  • NITIM (PhD network on Networks, Information Technology and Innovation Management) 2007 (“The Ecology of FLOSS 2.0: Attractiveness from outside the “Community”)
  • Workshop on Open Innovation, Cambridge University and MIT, 2007 (“Firms’ Decision to Contribute to Free Libre Open Source Software Communities”)
  • Doctoral Consortium of 15th European Conference on Information Systems (ECIS) 2007 (“New Business Models in FLOSS 2.0”)
  • ITS-Europe Regional Conference 2003 (“SMS Interactive TV - The Convergence of Television and Mobile Networks”)


  • Data Crawling (PhD course), LMU [Instructor]
  • Technology and Strategy (undergraduate), LMU [T.A.]
  • New Products: From Ideas to Markets (graduate), LMU [T.A.]
  • Data Analytics in Strategy Research (undergraduate), LMU [Instructor]
  • Management and Economics of Network Industries (undergraduate), LMU [T.A.]
  • Technology Innovation (undergraduate), UPF [Instructor]
  • Introduction to ICT (undergraduate), UPF [T.A.]
  • Business Administration II (undergraduate), UPF [T.A.]
  • Business Administration I (undergraduate), UPF [T.A.]
  • Information Systems (undergraduate), Universitat Ramon Llull [Instructor]
  • Innovation & Entrepreneurship (undergraduate), Universitat Ramon Llull [Instructor]
  • Applications Development (undergraduate), UPF [T.A.]
  • Telecoms Policy and Markets (undergraduate), UPF [T.A.]