Worried about getting old, outliving your money, or loneliness? You’ve got plenty of company.

By 2030, 1 in 5 Americans will be 65 or older, and by 2050, the US is projected to have nearly 1 million centenarians.

In her new book “The Second Fifty: Answers to the 7 Big Questions of Midlife and Beyond, ” Debra Whitman, an economist and AARP’s executive vice president, explores challenges and opportunities we all face as we age. These run the gamut from longevity to brain health, finances and jobs to housing, and, importantly, the role that relationships and social engagement play as the decades roll out.

Here's what Whitman had to say about navigating life after 50 with grace, good health, and firm financial footing, edited for length and clarity:

Kerry Hannon: Why are you optimistic about the challenges of aging?

Debra Whitman : I'm optimistic because older people are our fastest-growing natural resource. If we treated them as such and leveraged the value of experience, we could be driving GDP growth and fueling our economy , as well as giving people a bigger sense of purpose.

We overlook the contributions older people make and overestimate the need for care.

Plus, having a mindset that aging is a positive thing can affect our economics, but it also affects our personal health and well-being. If you have a positive view on aging, you live 7 ½ years longer than if you have a view that aging is a time of decline and despair.

You write that there are social reforms and medical reforms that can make a huge difference for people navigating the second half of life. Can you elaborate?

We need a national strategy on aging which encompasses everything from healthcare to financial security to making sure that long-term care works or transportation or housing systems are all integrated in looking at the needs of an aging society.

How is working as we get older good for us?

Working can be financially good for us. Many people need the money to supplement their Social Security checks or retirement savings. I was really surprised at how much of the gig workforce is people over age 50 — 20% of gig workers are 55-plus.

But working also can help us cognitively. If you have a stimulating job — one that challenges your brain — that can keep you healthier for longer. When we look at people who retire and don't have regular exercise or social interactions, just six years of retirement can raise their risk for illness and disability and affect cognitive function.

It could be through volunteer work, not paid work, but maintaining an active mind is really important as we age.

So Deb, you also talk about how we need to get creative about ways that people can continue to learn in order to participate in the workplace as they age. What are some of your ideas there?

The old model: You go to school, work, and then retire. But as our careers are getting longer, and as technology is changing rapidly, we need to disperse education throughout our working careers.

Often older workers aren't offered the opportunities for retraining. So I encourage people to seek that out through their employers, or externally, to keep their skills current. This is not just to help them with their current and potentially future jobs, but also just to continue to learn and to challenge their minds.

Can you debunk the myth about when employers retain older workers, it displaces younger workers?

The myth is that there's only so many jobs in the economy and so that anyone that has a job is taking it from somebody else. Actually, the opposite is true.

We have a desperate need to retain our older workers because in the next five years nearly 15 million Americans will retire from jobs. And employers will have to hire an average of more than a quarter of million people per month just to replace jobs being left by those who are retiring.

Second, having a five-generation workforce where you have multiple generations working together can actually improve the productivity of a firm. So companies that do retain their experienced talent and have them working as teams with younger workers can actually see better growth than those that don't have an age-diverse workforce.

One of the major issues of our time is the question of whether Social Security will be there for folks when they are ready to tap into it. You say, with confidence, yes. Why?

I've been working on Social Security issues since the start of my career. It was my first job out of graduate school. I’m frustrated that it hasn't been addressed sooner. Over a decade ago, I wrote a report at the Senate Aging Committee that said minor tweaks were all we needed.

There's no way that Congress and the White House can overlook this program in a time of crisis. If nothing is done in 2034, benefits for everybody in retirement will be cut by 20%. That impacts people with disability payments too. So I have confidence that the political winds will not let that happen and that a solution will be reached. I'm frustrated that it isn't happening now because the choices get tougher every year. But politically speaking I think the consequences of inaction are just too great.

What is the retirement age for Social Security, 401(k), and IRA withdrawals?

You've worked for more than a quarter of a century focused on building financial security for older Americans. Where do we stand right now?

I'm hopeful but frustrated. We have passed quite a few laws, such as Secure.2.0 on retirement savings, that have tweaked things around the edges.

And what's happening in the states is revolutionary, considering that half of the US population hasn't been able to easily save for retirement .

Now, we have 20 states that either have plans or are developing them, and when they do, we will no longer have these pockets of haves and have-nots where people can save for retirement or not, depending on who they work for.

I would like to see the entire country able to save for retirement. So that's what frustrates me. And I would like to make those plans that are out there even stronger for people so that they are able to accumulate the money that they need for their future.

How are people over 50 knocked down by losing a job at this age?

As Richard Johnson, director of the Program on Retirement Policy at the Urban Institute’s work, has found, half of people in their 50s will lose their jobs involuntarily. That’s when we're hitting the high point of our career, building up our savings.

Only 10% of those people who lost their job involuntarily will make the same amount when they get re-hired as they did at their last job.

I think the precarity of work in your 50s doesn't bode well for working until your 70s. People need to understand that life might be a little game of shoots and ladders where you're climbing up the ladder, and then you fall down a chute, and then you climb up the next one.

That's another reason why having our skills current and making sure that we continue to connect with others and look at other types of employment that might be of interest to us needs to continue throughout our second 50.

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Kerry Hannon is a Senior Columnist at Yahoo Finance. She is a career and retirement strategist, and the author of 14 books, including " In Control at 50+: How to Succeed in The New World of Work" @kerryhannon .

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