Fourteen months have passed since the European Union’s General Data Protection Regulation (GDPR) came into force and now an academic study suggests that recorded page views, site visits and revenue at online firms have fallen as a result.

According to Samuel Goldberg (Northwestern University), Garrett Johnson (Boston University) and Scott Shriver (University of Colorado), recorded page views and site visits fell by 9.7% and 9.9% respectively since the introduction of the GDPR.

They also estimate that revenue at e-commerce sites in Europe declined by 8.3%, equating to lost income worth $8,000 a week for the median site.

The three academics presented their findings at a recent conference hosted by the National Bureau of Economic Research in Massachusetts and asserted that their study was one of the first of its kind into the impact of the GDPR on European web traffic and e-commerce sales.

Entitled Regulating Privacy Online: The Early Impact of GDPR on European Web Traffic and E-commerce, the report covered 1,500 online firms that use the Adobe Analytics platform, including 128 of the top 1,000 sites in the world, and which are visited about one billion times a week by consumers in the EU.

Goldberg, Johnson and Shriver argue that one possible explanation for the declines in traffic and revenue is because the GDPR increased the legal risk associated with email and online display advertising, which both rely on personal data in the form of cookies or email lists. “As such, the quality and quantity of advertising through these channels may fall,” they write.

Secondly, all those pop-ups asking consumers for permission to share their data may have affected how people approach their site visits. “GDPR enforcement brought ubiquitous privacy notices on websites that serve EU users,” the academics explain.

“By increasing the salience of privacy concerns, these notices may have changed user preferences for how much time users spend online and which sites they frequent.”

However, an article in MIT Technology Review cautioned that the almost 10% drop in page views, site visits and revenue might not be as dramatic as it seems because the research depends on data gathered from Adobe Analytics, which is also subject to the GDPR and that could mean fewer people in Europe are sharing data with it.

“In other words, there might be a group of people who are browsing and buying just as much as before, but aren’t showing up in the Adobe data set,” wrote MIT Technology Review’s Angela Chen.

Sourced from National Bureau of Economic Research, MIT Technology Review; additional content by WARC staff