Defining the American Dream used to be relatively easy for many people.

It meant your family was intact, your career was on an upward trajectory, and maybe you were able to close the deal on that house in the suburbs.

But the numbers are telling us that fewer and fewer Americans are actually able to achieve that dream.

Robert Fluegge, a predoctoral fellow at Stanford’s Institute for Economic Policy Research, worked with Professor Raj Chetty on the Equality of Opportunity Project. In part, it measures the chances Americans — or people in other nations — have of achieving the American Dream.

We spoke with Fluegge.