As false news has become a global phenomenon, scholars have responded. They’ve ramped up their efforts to understand how and why bad information spreads online — and how to stop it. In the past 18 months, they’ve flooded academic journals with new research and have raised the level of urgency. In a March 2018 article, titled “The Science of Fake News,” in the prestigious journal Science, 16 high-profile academics came together to issue a call to action, urging internet and social media platforms to work with scholars to evaluate the problem and find solutions.

Much of what researchers have learned in this short time helps to answer three important questions — about how much misinformation people consume, why they believe it, and the best ways to fight it.

How far does misinformation reach?

Researchers are still trying to get a clear picture of how many people are influenced by false news and its digital reach. For now, they have been able to make estimates on the basis of survey data, geography, and other sources.

For example, a 2017 study in the Journal of Economic Perspectives examined the consumption of false news in the US during the months leading up to the 2016 presidential election. In a survey of 1,208 U.S. adults, 15 percent said they remembered seeing false news stories, and 8 percent acknowledged seeing one of these stories and believing it. The study’s authors — Hunt Allcott, an associate economics professor at New York University, and Matthew Gentzkow, an economics professor at Stanford University — estimated that US adults, on average, “read and remembered on the order of one or perhaps several fake news articles during the election period.”

Earlier this year, the Reuters Institute for the Study of Journalism at the University of Oxford released a report showing that false news sites appear to have a limited reach in Europe. For instance, in France, where Russians are accused of trying to interfere with the most recent presidential election, most of the false news sites studied reached 1 percent or less of the country’s online population each month in 2017. However, when researchers looked at how people interacted with false news on Facebook — via shares and comments, for example — “a handful of false news outlets in [the] sample generated more or as many interactions as established news brands.”