An anonymously funded program that pays the college tuition of students from the Kalamazoo public school district in Michigan has given out $67 million in scholarships since being announced 10 years ago.

Close to 4,000 students have taken advantage of the program called the Kalamazoo Promise. Students have earned more than 850 degrees and post-secondary credentials.

A study released this summer by the W.E. Upjohn Institute for Employment Research shows students eligible for the program are a third more likely to graduate from college within six years of finishing high school. The study compared them with their peers before the Promise existed.

The program has become a model for similar initiatives elsewhere. Dozens of communities across the U.S. now offer free-tuition strategies modeled after Kalamazoo's.