Competition and Defaults in Online Search
首次系统量化评估了旨在削弱谷歌搜索主导地位的默认选项干预措施，发现其在欧洲经济区、俄罗斯和土耳其均有效降低了谷歌市场份额，但影响幅度因干预细节而异。
This paper offers the first systematic quantitative assessment of default-option interventions designed to mitigate Google's search dominance. By analyzing interventions in the European Economic Area (EEA), Russia, and Turkey, we find that across all three cases, changes to default settings effectively reduced Google's market share. The causal impact amounts to less than 1 percentage point in the EEA and over 10 percentage points in Russia and Turkey. Differences arise from intervention nuances, including the size of the targeted users' group, local market characteristics, and remedy designs. We discuss the complexity of assessing the interventions' impact on welfare deriving from quality responses.