I am an assistant professor (non-TT) at the Institute for Information Business of the Vienna University of Economics and Business (WU Wien). I am also affiliated with the Complexity Science Hub. I am currently studying how large groups of people work together online on platforms like Github and Stack Overflow. I am especially interested in applying the methods of complexity science to understand how these communities grow and sustain themselves.
Before moving to Vienna I was a postdoc with Markus Strohmaier at the Chair for Computational Social Sciences and Humanities at RWTH Aachen. Before that I wrote my dissertation, supervised by János Kertész at Central European University, on the application of network methods to the study of corruption. During my PhD I was a visitor at the Oxford Internet Institute, the Hertie School of Governance, and the Hungarian Academy of Sciences.
September 2020: I'll be giving a keynote at the Corruption Networks Satellite at NetSci in Rome. Details coming soon!
June 2020: We have a new preprint out on how gamification affects developers.
June 2020: Our latest paper on changes in procurement market structure across elections is now published in a special issue of Politics and Governance.
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.
The Effects of Gender Signals and Performance in Online Product Reviews. [Link]
Sandipan Sikdar, Rachneet Singh Sachdeva, Johannes Wachs, Florian Lemmerich, Markus Strohmaier
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
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
SocArxiv, DOI: 10.31235/osf.io/qgpve, 2019.
Research Praktikum, RWTH Aachen Winter Semester 2019-2020
Social Data Science, course instructor, RWTH Aachen Winter Semester 2019-2020
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:
--- 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