Ad blocking software allows Internet users to obtain information without generating ad revenue for site owners, potentially undermining investments in content. We explore the impact of site-level ad blocker usage on website quality, as inferred from traffic. We find that each additional percentage point of site visitors blocking ads reduces its traffic by 0.67% over 35 months. Impacted sites provide less content over time, providing corroboration for the mechanism. Effects on revenue are compounded; ad blocking reduces visits, and remaining visitors blocking ads do not generate revenue. We conclude that ad blocking poses a threat to the ad-supported web. , for constructive suggestions. Last, we would like to thank participants for helpful suggestions at numerous seminars [Brandeis University (

With digital music as its context, this paper quantifies how much money would be made using alternatives to uniform pricing. Using survey-based data on nearly 1,000 students' valuations of 100 popular songs in early 2008 and early 2009, we find that various alternatives can raise both producer and consumer surplus. Digital music revenue could be raised by between a sixth and a third relative to profit-maximizing uniform pricing. While person-specific uniform pricing can raise revenue by over 50 per cent, none of the non-discriminatory schemes raise revenue's share of surplus above 40 per cent of total surplus. *We thank the Mack Center at Wharton for financial support. Tom Holmes provided helpful comments on an earlier draft, and we thank referees and the Editor for additional input. We are also grateful to seminar participants at Kellogg, Ohio State, Michigan, the NBER 2008 Summer Institute IO group, QME, INFORMS in Washington, and ZEW in Mannheim for comments. All errors are our own. † Authors' affiliations: Brandeis University,

No abstract

No abstract

Firms are increasingly able to monitor and collect proprietary data on their customers' behaviors, raising concerns among antitrust authorities that incumbents may use such data to soften competition. Focusing on auto insurance monitoring programs which offer tailored discounts to consumers driving safely, we examine the impact of proprietary data collection on incumbent profits. We find that incumbents' profits initially increase but are eroded by competition from other firms offering similar programs. We further find that these monitoring programs reduce fatal accidents. Yet the benefits are short-lived. Incumbents, who do not necessarily internalize the full costs of accidents, typically monitor their customers only temporarily. Thus, regulation incentivizing permanent monitoring may improve welfare by reducing moral hazard.