Two economists—Lesley Chiou and Catherine Tucker—studied search engines that took advantage of differences in data-retention practices.8 In response to the EU’s recommendations in 2008, Yahoo and Bing reduced the amount of data they kept. Google did not change its policies. These changes were enough for Chiou and Tucker to measure the effects of data scale on search accuracy. Interestingly, they found scale didn’t matter much. Relative to the overall volume of data that all the major competitors used, less data did not have a negative impact on search results.
