It is clear that the death of Islamic State leader Abu Bakr al-Baghdadi will damage the organizational and strategic capacity of the already beleaguered Islamic State. But will it meaningfully undermine the popularity of Baghdadi’s militant ideas? Data we analyzed from jihadi websites suggests that the answer is no.

The death of al Qaeda head Osama bin Laden on May 2, 2011, sparked a debate about whether his death might help lessen the appeal of his ideas or inadvertently make them more popular than ever. Commentators such as Abdel Bari Atwan warned of the “danger that post-Bin Laden, al-Qaida may emerge even more radical, and more closely united under the banner of an iconic martyr.” While others, such as Robin Simcox writing in the Los Angeles Times, rebutted that “Rather than making him a martyr, Bin Laden’s killing demonstrated that he was, like the rest of us, mortal.”

Events since don’t clearly show which of these arguments is right. On one hand, jihadism has hardly waned since bin Laden’s death in 2011. On the other, it is the upstart Islamic State group that has seized the mantle of violent jihad, not a more unified al Qaeda. Yet the question still matters: If killing bin Laden reinvigorated his ideas, then we might worry that the death of Baghdadi will invigorate a defeated but regrouping Islamic State.

To answer this question, we collected daily counts of page views to every one of over 6,000 documents posted to the largest online library of jihadi material from 2011 to 2014, with 30,000 to 60,000 visitors per day from Algeria, Egypt, Morocco, Tunisia, and other Arabic-speaking countries. The website is primarily a repository of texts, with no flashy graphics or slick videos to draw in curious outsiders. In short, these visitors are interested in jihadi ideas.

The ideas of jihadi writers do not become less popular after they die. Instead, their deaths made them temporarily more popular. From 2011 to 2014, 11 of the jihadi authors under study were killed, and 19 were captured. A look at traffic to their posts show that the ideas of jihadi writers do not become less popular after they die. Instead, their deaths made them temporarily more popular. These spikes start when their deaths are announced and last for about a week, matching the news cycle.

For example, when bin Laden was killed, his traffic jumped by a factor of 10: from 152 page views the day before to 1,923 the day after. All told, the spike in traffic ended up totaling approximately 10,000 extra page views before going back to baseline. The pattern suggests that any so-called martyrdom bump is short-term rather than long. But it should still give US counterterrorism practitioners pause to know that bin Laden’s death did lead to a substantial increase in interest in his violent ideas, even if temporarily.

We don’t have the same kind of data for Baghdadi’s death; this particular jihadi website has been offline since 2014. But after seeing consistent results for 11 other killed jihadis, it is safe to say that Baghdadi’s ideas are going to trend, at least temporarily.

In contrast to the jihadis who were killed, those who were captured never became more popular after their detainment was announced. This suggest that capturing jihadis is the best way to muzzle them without making their current writings more popular. Of course, capturing jihadis takes more manpower and carries more risk—and there is an element of luck: In Baghdadi’s case, he appears to have preempted capture by detonating a suicide vest. But the data suggests that if it had been possible to capture him, it might have avoided a spike of interest in his ideas.

Whether Baghdadi had been captured or killed, US officials surely hope that his death will be the end of the group, but just as the Islamic State morphed out of its predecessor group, the down-and-out organization now laying low in Syria and Iraq is likely to morph into something else. Like al Qaeda before it, the Islamic State has become a franchise organization centered around a set of aims and ideas, rather than a hierarchical organization centered around a single charismatic individual.

Baghdadi’s Islamic State introduced important new ideas to jihadi ideology, most importantly that governing territory and proclaiming a caliphate was an option for a jihadi group on the rise. His death does not seriously undermine this idea, and future jihadis will likely invoke the Islamic State’s logic (and branding) to justify similar goals. The franchise nature of the Islamic State will make it difficult to tell if future iterations are resurgent parts of the original organization or unconnected upstarts inspired by Baghdadi’s vision. It won’t matter much, because both will be genuine challenges to national and international security.

Of course, killing Baghdadi was not a mistake for a host of reasons. But data shows no reason for optimism that the idea of a jihadi Islamic State will die with him.

Santiago Segarra is an assistant professor of electrical and computer engineering at Rice University.

Ali Jadbabaie is the JR East professor of engineering and the associate director of the Institute for Data, Systems, and Society at the Massachusetts Institute of Technology.

Richard Nielsen is an associate professor of political science at the Massachusetts Institute of Technology.