The Web is the largest human information construct in history transforming our society. How can we understand, measure and model the Web evolution in order to design effective policies and optimize its social benefit? Early measurements of the Internet traffic and the Web graph indicated the...

The aim of this article is to evaluate, from an economic perspective, the efficiency of Web 2.0. It demonstrates that, because of the non-monetary nature of Web 2.0, several sources of inefficiencies (search costs, externalities, crowding out and adverse selection) exist. Nonetheless, the...

This paper reports the results of experiments designed to test whether individuals interacting on Facebook are more likely to succumb to the conjunction fallacy when they post their answers publicly and are exposed to the answers of others. Using the experimental design in Kahneman and Tversky...

Advertisers seek to maximize profits by investing in advertising. We propose a “cost-per-incremental-action” (CPIA) pricing model which incorporates the causal contribution of advertising in order to achieve the advertisers' objectives such as profit maximization. CPIA pricing aligns...

We propose a new method which allows for measuring separately taste based discrimination from statistical discrimination in the hiring process. We consider two types of statistical discriminations against women: first, when a recruiter doubts the productivity of the workers; second, when a...

Ranking algorithms are the information gatekeepers of the Internet era. We develop a stylized framework to study the effects of ranking algorithms on opinion dynamics. We consider rankings that depend on popularity and on personalization. We find that popularity driven rankings can enhance...

We find display advertising influences customer search for both the advertised brand and its competitors. We exploit a natural experiment that randomizes ad delivery on 500 million visits to the Yahoo! homepage and compare visitors' subsequent activities on Yahoo! Search. In three advertisers'...