Some people scam the system to get jobless benefits they don’t deserve. But far more don’t claim the benefits for which they are eligible, according to research by economists working with the Federal Reserve Bank of St. Louis.

In 2009, for example, the federal and state governments paid almost $121 billion in unemployment insurance, including $11 billion in overpayments.

If everyone eligible for jobless benefits that year had claimed them, the program would’ve had to shell out an additional $108 billion, according to an article by Concordia University economist David Fuller, St. Louis Fed economist B. Ravikumar and Texas A&M University economics professor Yuzhe Zhang. Their research was posted in the St. Louis Fed’s Regional Economist, a quarterly publication.