Johannes Wachs

Assistant Professor (non-TT)
Vienna Uni. of Economics and Business
Complexity Science Hub Vienna

About Me

I am an assistant professor (non-TT) at the Institute for Data, Process and Knowledge Management of the Vienna University of Economics and Business (WU Wien). I am also affiliated with the Complexity Science Hub. I study social, technical, and economic networks and their effects on society. I am particularly interested in how software systems and their creators shape the digital economy.

Previously I was a postdoctoral research at the Chair for Computational Social Sciences and Humanities at RWTH Aachen with Markus Strohmaier. My dissertation, supervised by János Kertész at Central European University, was on the application of network methods to the study of corruption. During my PhD studies I was a visitor at the Oxford Internet Institute, the Hertie School of Governance, and the Hungarian Academy of Sciences.

News and Updates

We welcome your contributions to a special issue on Data Science Perspectives on Economic Crime at EPJ Data Science. Deadline: December 1st.

We have a new preprint out on the geography of Open Source Software developers. We are grateful for feedback and comments! [Link]. The data are also available here: [Link].


How Gamification Affects Software Developers: Cautionary Evidence from a Natural Experiment on GitHub. [Link]

Lukas Moldon, Markus Strohmaier, Johannes Wachs
IEEE/ACM 43rd International Conference on Software Engineering (ICSE), 2021.
Summary on YouTube: [Link]

Does crowdfunding really foster innovation? Evidence from the board game industry. [Link]

Johannes Wachs and Balázs Vedres
Technological Forecasting and Social Change (2021).

Writer movements between news outlets reflect political polarization in media. [Link]

Nick Hagar, Johannes Wachs, Emőke-Ágnes Horvát
New Media & Society (2021).
---- Der Tagesspiegel (DE): Journalistische Filterblasen.
---- Niskanen Center Science of Politics Podcast (EN): How the Media Economy Drives Political News.
---- RQ1 (EN): How the pandemic (sort of) changed our news habits.

Inequality is rising where social network segregation interacts with urban topology. [Link]

Gergő Tóth, Johannes Wachs, Riccardo Di Clemente, Ákos Jakobi, Bence Ságvári, János Kertész, Balázs Lengyel
Nature Communications (2021).
---- Der Standard (AT): Wie das Stadtbild Ungleichheiten verstärkt.
---- le Scienze (IT): Il peso della geografia urbana sulle disparità tra cittadini.
---- (HU): Bár az iWiW halott, az adatbázisából kutatják, miként csökkenthetők az egyenlőtlenségek.
---- UPI (EN): For more equitable cities, researchers say to keep social networks intact.
---- Qubit (HU): A rég halott iWiW kincset érő adatain mutatták ki, hol nőhet az egyenlőtlenség Magyarországon.

No country for asylum seekers? How short-term exposure to refugees influences attitudes and voting behavior in Hungary. [Link]

Theresa Gessler, Gergő Tóth, Johannes Wachs
Political Behavior (2021).

Mining DEV for Social and Technical Insights about Software Development [Link]

Maria Papoutsoglou, Johannes Wachs, Georgia M. Kapitsaki
2021 IEEE/ACM 18th International Conference on Mining Software Repositories (MSR) 2021.

Complexity science approach to economic crime [Link]

János Kertész and Johannes Wachs
Nature Reviews Physics, 2021.

Corruption and the Network Structure of Public Contracting Markets across Government Change [Link]

Mihály Fazekas and Johannes Wachs
Politics and Governance, 2020.

Corruption risk in contracting markets: a network science perspective. [Link]

Johannes Wachs, Mihály Fazekas, and János Kertész
International Journal of Data Science and Analytics, 2020.

A network approach to cartel detection in public auction markets. [Link]

Johannes Wachs and János Kertész
Scientific Reports, 2019.

Gender Differences in Participation and Reward on Stack Overflow. [Link]

Anna May, Johannes Wachs, Aniko Hannak
Empirical Software Engineering, 2019.

Social capital predicts corruption risk in towns. [Link]

Johannes Wachs, Taha Yasseri, Balázs Lengyel, János Kertész
Royal Society Open Science, 2019.

The Role of Novelty in Securing Investors for Equity Crowdfunding Campaigns. [Link]

Emőke-Ágnes Horvát, Johannes Wachs, Rong Wang, Aniko Hannak
AAAI Conference on Human Computation and Crowdsourcing (HCOMP), 2018.

And Now for Something Completely Different: Visual Novelty in an Online Network of Designers. [Link]

Johannes Wachs, Balint Daroczy, Aniko Hannak, Katinka Pall, Christoph Riedl
Proceedings of the 10th ACM Conference on Web Science (WebSci), 2018.

Why Do Men Get More Attention? Exploring Factors Behind Success in an Online Design Community. [Link]

Johannes Wachs, Aniko Hannak, Andras Voros, Balint Daroczy
Proceedings of the 11th International AAAI Conference on Weblogs and Social Media (ICWSM), 2017.

Policy Papers

Gender in European public procurement: Extent, distribution, and impacts. [Link]

Mihaly Fazekas, Yuliia Kazmina, Johannes Wachs
European Bank for Reconstruction and Development (EBRD) Research Paper, 2020 .


From Asking to Answering: Getting More Involved on Stack Overflow. [Link]

Timur Bachschi, Aniko Hannak, Florian Lemmerich, Johannes Wachs
arXiv:2010.04025, 2020.

The Effects of Gender Signals and Performance in Online Product Reviews. [Link]

Sandipan Sikdar, Rachneet Singh Sachdeva, Johannes Wachs, Florian Lemmerich, Markus Strohmaier
arXiv:2001.09955, 2020.

Selected Grants and Prizes

2021-2024: Crisis Response and Intervention Supported by Semantic Data Pooling (CRISP), supported by the FFG's "ICT of the Future" program
October 2020: Our team won the IMF Anti-Corruption Challenge!
2020-2021: Geography of Open Source Software, supported by the City of Vienna-WU Jubilee Fund
2020-2021: Data Set Re-Use, supported by the WU Projects fund


Applied Data Science: Computational Social Science, Vienna University of Economics and Business, repeating
Research Praktikum, RWTH Aachen Winter Semester 2019-20
Social Data Science, course instructor, RWTH Aachen Winter Semester 2019-20
Social Networks, course instructor, RWTH Aachen Summer Semester 2019
Using Big Data for social science research, teaching assistant, CEU Spring 2017
Data Mining, course instructor, AIT Fall 2016
Scientific Python, teaching assistant, CEU Fall 2016, 2017

Selected Student Theses:
--- Jeremias Brändle, Analysing the Impact of Corruption on Innovation Performance in European Regions. Bachelor's Thesis, WU Wien, 2021. [PDF]
--- Lukas Moldon, Sending signals in open source: Evidence from a natural experiment. Bachelor's Thesis, RWTH Aachen, 2020. [PDF]
--- Timur Bachschi, From Asking to Answering: Social and Structural Aspects of Contributing to Stack Overflow. Bachelor's Thesis, RWTH Aachen, 2020. [PDF]


PhD Network Science, summa cum laude, Central European University (2019)
MS Applied Mathematics with distinction, Central European University (2012)
BS Mathematics, BS Economics, cum laude, Tulane University (2009)


johanneswachs at gmail dot com