2025 Theses Doctoral

Essays on Economics of Media

Beknazar-Yuzbashev, Gevorg

This dissertation investigates how digital media platforms shape user behavior and social outcomes through advertising, content curation, and informal social norms. Across three essays, I study (i) how platforms effectively ``price'' attention using advertising loads, (ii) how exposure to toxic content affects engagement and welfare, and (iii) whether informally compelled compliance with an emerging norm generates backlash. Together, the essays combine structural theory, a large-scale field experiment with a custom browser extension, and online experiments to provide causal and policy-relevant evidence on the economics of media.

The first essay develops a simple model in which platforms choose advertising load while users choose time on platform, taking ad load and ad-match quality as given. In this framework, ad load functions as an implicit price on attention: higher loads raise marginal disutility and reduce time spent, while improvements in match quality offset this ``price''. I test these predictions using a preregistered field experiment that recruited nearly two thousand U.S. Facebook users and installed a custom desktop browser extension capable of varying both the quantity of advertisements and the degree of microtargeting in participants’ feeds. The extension recorded real-time exposure and behavior across three major platforms. I estimate treatment effects with a difference-in-differences design.

The second essay uses the same experimental infrastructure to exogenously reduce exposure to toxic content on Facebook, Twitter/X, and YouTube by hiding posts flagged as toxic in real time. A difference-in-differences design quantifies the causal impact on engagement. I find that lowering toxicity decreases user engagement across multiple metrics; for example, average time spent on Facebook falls by roughly ten percent relative to baseline. Users partially substitute toward non-treated sites, indicating cross-platform spillovers. To probe mechanisms and welfare, I pair the field evidence with a preregistered survey experiment that separately varies toxicity and measures both click/reveal behavior and a reading task as a welfare proxy. The combined evidence indicates that toxicity can be engagement-enhancing but welfare-reducing, highlighting a wedge between platform incentives and user well-being.

The third essay examines informal norm compliance and potential backlash. In an incentivized online experiment with politically conservative participants, I randomly apply ``norm pressure'' by forcing subjects to support moderation outcomes they oppose, and I measure behavioral (investment) and attitudinal (affective thermometer) responses. In the full sample, I detect no statistically significant backlash on pivotal moderation choices or attitudes. However, effects become directionally larger -- and in some cases significant -- within a subsample where the pressure binds most tightly (a ``uniform-vote'' setting), suggesting that compelled compliance can induce countervailing reactions among those most at odds with the target norm.

Taken together, the essays deliver three conclusions. First, advertising loads act as shadow prices on attention: increasing loads or degrading match quality reduces engagement, and the resulting elasticities are economically meaningful for platforms’ revenue choices and for regulators contemplating limits on personalization. Second, reducing exposure to toxic content causally lowers engagement and triggers substitution toward other sites, while welfare responses are mixed -- consistent with toxicity that propels use but does not improve users’ well-being. Third, norm-based interventions need to account for for the potential backlash in areas unrelated to the norm itself.

These findings speak to policy and design. Conceptually, they clarify how ``free'' social media is priced through ad load and targeting; empirically, they quantify trade-offs platforms face between engagement, revenue, and welfare; and normatively, they caution that interventions relying on pressure rather than persuasion can backfire where disagreement is deepest. The dissertation thus offers a unified view of the economics of media in which platform levers (ads and curation) and social forces (norms) jointly determine behavior, welfare, and the scope for effective regulation.