What are the roads not taken because students must take out loans for college? A collection of studies shows that the burden of student debt may well cause people to make different decisions than they would otherwise — affecting not just individual lives but also the entire economy.

For one thing, it appears that people with student loans are less likely to start businesses of their own. A new study has found that areas with higher relative growth in student debt show lower growth in the formation of small businesses (in this case, firms with one to four employees).

The correlation makes sense. People normally have only a certain amount of “debt capacity,” said Brent W. Ambrose, a professor of risk management at Pennsylvania State University and a co-author of a preliminary paper on the research along with Larry Cordell and Shuwei Ma of the Federal Reserve Bank of Philadelphia.

When students use up their debt capacity on student loans, they can’t commit it elsewhere. “Given the importance of an entrepreneur’s personal debt capacity in financing a start-up business, student loan debt, which cannot be discharged via bankruptcy, can have lasting effects later in life and may impact the ability of future small-business owners to raise capital,” the study says.