He spends his days proving the immigration line barely moves - and he has the spreadsheets to make a courtroom pay attention.
Ask most people why someone crosses a border illegally and you will hear a moral argument. Ask David J. Bier and you will get a probability. His most repeated line is not a slogan - it is a measurement: fewer than 1 percent of the people who want to move permanently to the United States can do so legally. He arrived at it the way he arrives at everything, by reading the statutes, pulling the visa data, and refusing to round up.
Today Bier is the Director of Immigration Studies at the Cato Institute, where he also holds the Selz Foundation Chair in Immigration Policy. The job, as he practices it, is less about opinion and more about arithmetic. When a cable host says the system is generous, he reaches for the green-card numbers. When a committee insists the rules just need to be followed, he points out that the rules were rebuilt in 1924 to presume nearly everyone ineligible. He is the person who shows up to an emotional fight carrying a chart.
That chart has traveled further than most. His research and writing have been cited by the U.S. Supreme Court and by multiple federal appeals courts - unusual company for a think-tank analyst whose primary tool is a footnote. His work appears in the New York Times, the Washington Post, the Wall Street Journal, USA Today, and Politico, and he has testified before House and Senate committees more times than is comfortable to count.
What makes Bier interesting is not that he defends immigration. Plenty of people do. It is that he treats the legal-immigration system as an engineering problem with a measurable failure rate, and then publishes the rate. The result is a body of work that is hard to argue with and harder to ignore.
The detail that explains Bier best is buried in his resume. Between 2013 and 2015 he was not critiquing immigration legislation - he was drafting it, as senior policy adviser to Representative Raul Labrador of Idaho, a member of the House Judiciary Subcommittee on Immigration and Border Security. He learned how a bill gets built, which clauses do real work, and which ones are there for the press release. Then he left the building and started keeping score.
Before Cato, he sharpened the same instincts at the Competitive Enterprise Institute and ran immigration policy at the Niskanen Center. By the time he settled into Cato's immigration shop, he had seen the system from the inside of a congressional office, from the advocacy bench, and from the data desk. Few analysts can say they have written the thing they now audit.
His 2023 report, "Why Legal Immigration Is Nearly Impossible," is the closest thing he has to a signature. It reframed a debate that usually runs on feeling into one that runs on odds. The Powerball line did the cultural work; the tables underneath did the durable work. The argument was not that people should break the law. It was that calling the legal path a real alternative is, statistically, a category error.
More recently he has trained the same lens on enforcement, arguing with the receipts that the most aggressive recent cuts landed on legal immigration even harder than on illegal immigration - an uncomfortable finding for anyone who claims to favor the former while squeezing it. In March 2025 he was back at a witness table, testifying on restoring immigration enforcement, doing what he does: bringing numbers to a place that prefers narratives.
The report that put a number on the bottleneck. Fewer than 1% can come legally; the burden of proof flipped onto the immigrant in 1924.
A repeat witness on border security, interior enforcement, and the mechanics of legal admission - arguing from data, not anecdote.
His finding that recent crackdowns blocked more legal immigrants than illegal ones - and why stated support for "legal immigration" rarely matches the record.
Bier has built a kind of credibility that does not depend on which side you are on. Reporters reach for him because his numbers hold up; opponents engage him because ignoring the data is worse than disputing it. He has turned up on the BBC, on CNN's Amanpour, on Chris Hayes's podcast, and across a long list of immigration-focused shows - not to perform outrage, but to translate policy into consequence.
The through-line is a refusal to let the conversation drift into vibes. Where others say the system is broken, Bier specifies how: a 1924 architecture that presumes exclusion, categories so narrow that most peaceful applicants never qualify, and odds so long that the legal path functions more like a lottery than a process. He is, in the most literal sense, trying to make the line move - and he keeps publishing the chart that shows it hasn't.
*$14.5T figure reflects Bier's research finding on immigrants' net effect on the national debt over 30 years.