Among the pernicious stereotypes about older employees is the snark they can't learn new technologies.

You've heard the expression: "You can't teach an old dog new tricks." Wrong, deeply wrong.

I was lucky with my first office job in the early 1980s. I used an IBM Selectric typewriter, and you could erase a line if you didn't hit enter. My career has since involved dedicated word processing machines, desktop computers, laptops, smartphones, tablets and many software programs. My experience is far from unusual.

Yet a recent report for the American Staffing Association by Harris Poll showed how real age discrimination is. Seventy-eight percent of boomers surveyed think age would be a factor when in consideration for a new position, and 68% believe their age puts them at a disadvantage when finding a new job. Age discrimination is wrong, including negative perceptions about older workers and new technologies.

Age discrimination is a barrier to employment in retirement. Yet working longer is financially savvy. For one thing, a job makes it practical to delay filing for Social Security, a boon to benefits. For another, part-time work, flexible jobs and other ways of earning a paycheck allow for adding to savings. Not everyone can or wants to stay on the job, of course.

The good news is the impact of age discrimination might be waning. That's my takeaway from a recent study by economist Geoffrey Sanzenbacher for the Center for Retirement Research at Boston College. The study, "Can Employer Demand Support Older Workers Today … And Tomorrow?," synthesizes previous research from the center.

"Overall, room for optimism exists," he wrote.

Briefly, Sanzenbacher found no clear evidence supporting the notion older workers are less productive than their younger peers. There is no significant difference between younger and older workers when measuring corporate profitability in most industries. Employer surveys say management recognizes the benefits of older workers, though jobs targeted at older workers tend to pay less and come with fewer benefits. Looking out to 2030, "while older workers may need to change with the times and enter some new occupations, their skills should enable them to do so," he wrote.

The desire to work longer will swell with the aging of the workforce. Older workers should have the option, assuming reasonable health. Whether and how to earn an income is critical to retirement planning. And, for employers, older workers are a valuable asset to keep and to hire.

Chris Farrell is senior economics contributor, "Marketplace"; commentator, Minnesota Public Radio.