Immigration policy has been a key focus of the Trump government. The administration’s recent proposal would drastically reduce legal immigration in exchange for extending DACA protections. Chances are your mind is already made up on this issue, but how well do you understand the logic on each side of the debate? And which side does the research evidence support?

Thicket’s “Lists” provide an interactive visual overview of current policy debates–like immigration–mapping out the flow of arguments and connecting claims to research evidence. This List on immigration focuses on two major policy questions: how much should the government restrict immigration and why? And what should the government do about people who are undocumented?

Two of the claims made in support of restricting immigration are economic arguments: the idea that immigrants compete with natives for jobs, and the claim that immigrants divert welfare resources from natives. But as you can see on Thicket, these claims are contradicted by most research. The claims are also contradicted by other economic arguments supporting more immigration: the arguments that immigration can boost the native workforce by augmenting their skills and productivity, and that immigration can boost innovation by bringing new ideas.

Thicket shows how these contradictory claims have been investigated by research. In the academic and policy world the conversation has centered on questions of how immigrants affect local economies, often focusing on specific types of immigrants and their impact on specific segments of local populations. Most research finds that immigration has negligible impact on local economies and labor markets. However, one prominent voice in academia has long been arguing immigration is detrimental: Harvard Kennedy School economist George Borjas has found negative effects from immigration in a multitude of papers in his career. He recently published an op ed in the New York Times, more or less supportive of Trump’s immigration proposal and of “putting everything on the table.” In particular he argues for limiting “chain migration”, where a single immigrant can bring in their entire extended family. This concern ignores the fact that immigration and naturalization is a difficult, rigorous process that can take generations. It is not at all permissive, and potential immigrants are carefully screened.

Michael Clemens is another economist that has done significant work on immigration and just provided an analysis of the impact of Trump’s proposal on different populations in the United States, complete with a spreadsheet you can play around with at home. Clemens has also recently published research with Jennifer Hunt rebutting some of Borjas’s recent work, taking issue with some of Borjas’s methods.

The immigration debate can get heated, which is understandable. But even passionate rhetoric–especially passionate rhetoric–needs to based in sound reasoning and real data. Thicket connects the arguments we hear from politicians or read in the news to the facts as established by expert researchers in peer-reviewed work, providing sound footing for better debate and ultimately better policy.