MEASURING THE EFFECT OF NAPSTER ON RECORDED MUSIC SALES: DIFFERENCE‐IN‐DIFFERENCES ESTIMATES UNDER COMPOSITIONAL CHANGES
Napster对唱片销量的影响:构成变化下的双重差分估计
SUMMARY This paper measures the effect of Napster on record sales. I treat the introduction of Napster as a technological event that only Internet users experienced, and use a difference‐in‐differences (DD) approach. Because of potential compositional changes in Internet users, I examine identifying assumptions for the DD estimator under compositional changes and develop a test for identifying restrictions. To address potential bias due to compositional changes, I extend DD…