According to the Population Reference Bureau, the number of Americans 65 and older is expected to double from 46 million in 2016 to over 98 million by 2060. It means a huge chunk of the population will be leaving the workforce, resulting in a scarcity of talent in certain sectors. Yet a wealth of studies have been conducted which indicate that if people stay working longer, they're often better off for it. Here are a few to consider.

1. People who retire early, tend to die sooner.

That's according to researchers at Oregon State University who found that healthy people who retired a year beyond the age of 65 had an 11 percent decreased chance of dying, compared with those who retired earlier. What's more, study participants who labeled themselves as unhealthy were found to live longer if they continued working.

2. Retirement can dull your cognitive ability.

Dr. Esteban Calvo, a sociologist at Columbia University, has conducted research which indicates there's truth to the maxim "use it or lose it." Novelty and social interaction have much to do with keeping a mind in good working order.

3. Retiring increases the probability of clinical depression.

That's according to research (PDF) presented by the Institute of Economic Affairs, which analyzed data on retirement and health and found the longer a person is retired, the more health problems he or she has. When it comes to mental wellness, the IEA determined that retirement makes a person about 40 percent more likely to suffer from clinical depression.

4. Owning a franchise is an alternative.

Whether they can't afford to retire, or prefer staying busy, more people are choosing to start a second career in their golden years. At 91, Bob Thomson owns several restaurants within the Subway Sandwiches and Pancheros Burritos franchise organizations, with the latter having recently named him "Franchisee of the Year." He says he's happy working decades past the magical age of 65, and anybody else can be too, as long as they research what they're getting into. He says it's vital to vet the hell out of any franchise, make sure you want to married to the job for several years, and get a territory as protection against cannibals.

5. Volunteering helps.

If you really believe leaving the rat race would make you happy, you can mitigate the health risks of retirement by helping others. Researchers (PDF) have consistently found that older people who volunteer experience improved health, increased physical functioning, better cognitive ability, lower rates of depression and longer lives.