We quantify the prevalence of undisclosed influencer posts on Twitter across a large set of brands based on a unique data set of over 100 million posts. We develop a novel method to detect undisclosed influencer posts and find that 96% of influencer posts are not disclosed as such. Despite...

I present the following proposal: information revealed during non-cartel investigations by competition law enforcement authorities, such as evaluation of M&As or investigation of monopolization (dominance) conduct, should be directly used to investigate and prosecute cartels. Currently, in...

This paper studies how a firm should make pricing and transparency decisions when consumers care about supply chain characteristics. We first show how preferences that account for price and unit cost constrain the firm’s pricing power and profit. Surprisingly, we find that the firm may be...

We study the nature of peer effects in the market for new cell phones. Our analysis builds on de-identified data from Facebook that combine information on social networks with information on users' cell phone models. To identify peer effects, we use variation in friends' new phone acquisitions...

Firms often discourage certain categories of individuals from buying their products, seemingly at odds with typical assumptions about profit maximization. This paper provides a potential rationale for such firm behavior: Consumers seek to signal that they have "desirable" ideological values to...

We model competition on a credence market governed by an imperfect label, signaling high quality, as a rank-order tournament between firms. In this market interaction, asymmetric firms jointly and competitively control the underlying quality ranking's precision by releasing individual...

The adtech industry plays a key role in facilitating connections between digital publishers and advertisers. This paper studies the impact of vertical integration between an intermediary and a major publisher on the online advertising ecosystem and the provision of content. We find that vertical...

This paper investigates the differential response of male and female voters to competitive persuasion in political campaigns. During the 2011 municipal elections in Milan, a sample of eligible voters was randomly divided into three groups. Two were exposed to the same incumbentś campaign but to...

This paper empirically investigates the advertising competition in the French broadcast television industry within a two-sided market framework. We use a unique dataset on the French broadcast television market including audience, prices, and quantities of advertising of twenty-one TV channels...

We use high frequency data on TV and radio advertising together with data on online sales for lottery tickets to measure the short run effects of advertising. We find them to be strong and to last for up to about 4 hours. They are the bigger the less time there is until the draw. We develop the...