CORVALLIS — The “empty nest” of past generations, in which the kids are grown up and middle-aged adults have more time to themselves, has been replaced in the United States by a nest that’s full — kids who can’t leave, can’t find a job and aging parents who need more help than ever before.

According to a new study by researchers at Oregon State University, what was once a life stage of new freedoms, options and opportunities has largely disappeared.