According to Linda Jacobsen, what is NOT the reason for senior Americans to work

Analysts at the US Census Bureau have a provocative forecast for America’s population in 2050, when today’s 25-olds will be knocking on the door of age 65.
    If projections hold, not only will there be more than TWICE as many people 65-and-over in sheer numbers as there are now, but their percentage of the population will jump from 12 percent today to 21 percent. That means more than one in five Americans at mid-century will be what we call "senior citizens." And if current demographic trends continue, a much greater proportion of the nation’s elderly will be Hispanic, African-American and Asian-American.
    Linda Jacobsen at the Population Reference Bureau helped us sort out the implications:
    Primarily, she says, in 2050 a whole lot more people 65 and older will be on the job outside the home. In part, that’s because many more than today will be well educated and in rosy health, and will simply WANT to keep working.
    Others won’t have a choice, since they won’t be able to get Social Security benefits as the eligibility age keeps rising, quite possibly to 70 or beyond by 2050. And as private companies cut costs, generous pension and company-paid retirement accounts will be harder to find as well.