It’s the worst-kept secret in the Garden State: People are leaving the state in droves — New Jersey has the highest out-migration rate in the nation — and those who stay aren’t doing well.

But New Jersey is also the nation’s leader in another troubling, underappreciated category: Nearly half — 48 percent — of New Jersey’s young adults are living with their parents, more than in any other state.

Let that sink in. Tens of thousands of people in their prime — who should be building their dreams — are stuck in Mom and Dad’s basement.

Living with the parents means other dreams are being put on hold, like getting married, having a family or starting a business. As a millennial myself, I was fortunate to get married a few weeks ago. But 71 percent of young adults in the state have never been married.

Everyone has to accept disappointment in life, but far too many young New Jerseyans are getting used to disappointment being the status quo. And far too many families are literally being broken up as generations move out of state. I asked around recently — what’s life like in the Garden State for millennials?

“I’m living at home, have three degrees and can’t find a paying job anywhere! I’m currently working for free so I have some experience to put down on my résumé,” one 30-year-old attorney told me.

Don’t believe me when I say New Jersey’s economy is breaking up families? Then don’t take it from me, take it from a retired mother of three adult children, who said: “We have three kids living in three different states who will never return! They are asking us when we are leaving.”

“Even with a master’s degree, it’s difficult to be able to save, pay loans and work towards owning a home . . . taxes continue to increase but salaries do not,” responded a 29-year-old counselor. “I find it bothersome that as young adults, we have to settle because the job market continues to be stagnant.”

These aren’t unmotivated slackers — 30 percent of New Jersey’s 18- to 34-year-olds have a bachelor’s degree, compared to 22 percent in the rest of the nation. They’re educated, yet they struggle to find work. New Jersey has the highest unemployment rate in the region and one of the highest rates in the nation at 5.7 percent.

As NJ.com reported last year, “The state’s 18- to 34-year-olds still earn more than the rest of the country, with a median income of more than $41,000, but this too has declined in recent years. When adjusted for inflation, the state’s young adults are earning about $4,000 less than they did in 1990.”

And though you wouldn’t know it from the lack of solutions coming from New Jersey’s politicians, the reason for the stagnant economy is no mystery. Young people can’t find work because the state’s entrepreneurs and business owners are struggling to create new jobs. In fact, many companies are moving out. Hertz and Mercedes-Benz are just the most recent high-profile companies to move their addresses — and the jobs they provide — out of state.

It’s little wonder these companies find New Jersey’s soil isn’t fertile for business: The state’s No. 3 among the 13 worst states to do business, according to Business Insider. With a 9 percent corporate-income-tax rate and an 8.97 percent personal-income-tax rate, it’s little wonder New Jersey isn’t an entrepreneur’s paradise.

The high tax burden means that even those who are fortunate to find work face a substantially higher cost of living. Of course, if you manage to purchase a home in New Jersey, you’ll literally be paying its exorbitant property-tax rates until you die. Starting out in New Jersey means that millennials stay at home with their parents longer to pay off student debt or save for a house or wedding.

It’s time for a new generation of New Jerseyans to demand a better future — one that welcomes their dreams and treats them as a partner rather than just another source of tax revenue. They should demand that lawmakers stop taking the easy route of hiking taxes and instead cut the wasteful spending and excessive red tape that’s hampering job creation.

It’s time to bring opportunity back to New Jersey.

Erica Jedynak is the New Jersey state director of Americans for Prosperity.