If you earn a decent income but have trouble saving, the culprits could be the roof over your head and the car in your driveway.

Retirement savers who contribute more to their 401(k)s often spend less on housing and transportation than their peers, according to a study by the Employee Benefit Research Institute and J.P. Morgan Asset Management.

Better savers also spend less on food and drink, but housing and transportation are bigger expenses that tend to be less flexible. Once you commit to a place to live and a car payment, you’re typically stuck with those expenses for a while.

In my latest for the Associated Press, how your house and your car could be affecting your retirement savings.