No matter what you've heard from grumpy old people and angry politicians, Americans haven't gotten any lazier in the past 20 years. But while we might be just as willing to work hard, the same level of effort seems to buy less and less for many of us. Why is that?

That's the complex question at the heart of Squeezed, a new book digging into why middle-class life has become such a struggle for so many hard-working Americans. The book's author, journalist Alissa Quart, spoke with Knowledge@Wharton recently about what she discovered researching her book. It's a fascinating read (or podcast listen) for anyone who has ever wondered exactly why their paycheck stretches less and less far each year.

1. You can't afford to live where you can get a job.

"The main problem is the cost of housing -- at least that's what I found from my research and interviews -- especially in places like San Francisco, Los Angeles, and New York City," explains Quart to Wharton. That's probably no shock to anyone who has ever tried to make ends meet in the Bay Area or Manhattan, but Quart breaks down some of the underlying causes of the spike in house prices.

"In some of these desirable places, real estate is no longer a place to live but it's an investment vehicle. That has driven up the cost of housing for ordinary people or the precarious middle class, as I call them," she notes, for example.

2. Family unfriendly policies 

For a great many of us, having kids is an integral part of our dreams for our lives, but as soon as babies come along, the math of getting by in America gets much more difficult. The cost of day care is just astronomical, and our child-unfriendly policies make the calculus so much harder for families. Quart calls on people to consider "mobilizing for these so-called pie-in-the-sky things like better maternity leave."

She highlights, "There are laws against pregnancy discrimination; they're just not enforced." She points to the cultural shifts caused by #MeToo as a model: "This is something that people can do in the corporate sector. They can start saying, 'We'd better make sure these norms are enforced.'"

3. "Second act" student debt

The fact that young people today are incredibly burdened by student debt also won't surprise anyone, but Quart makes the point that, with globalization and tech changing the job market rapidly, more people are heading back to school for retraining later in life.

Too often the benefits are paltry but the financial cost is enormous. "I talked to a guy who is $60,000 in debt for getting retrained with a degree in IT from one of those for-profit colleges," Quart relates. "I think it has since been shut down. It was so corrupt, but he didn't know." She calls for more regulation of bad actors in the sector.

The solution: less shame and better laws

While not everyone will agree with Quart's mostly liberal-leaning policy prescriptions (though how anyone who believes in the perpetuation of the human species can be against decent paid family leave is beyond me), just about anyone who has struggled with the increasingly difficult math of being middle class in America should cheer her other prescription: less shame.

Many middle-class people feel ashamed of their difficulties, Quart found in the course of her research. "People are blaming themselves, saying, 'What did I do wrong? I did everything right. I got these degrees. I worked hard. Why is this not coming together?,'" she reports.

This shame isn't just a recipe for unhappiness; it's also a recipe for isolation. When we're embarrassed about our perceived flaws, we don't discuss our problems and the collective solutions we need. The math shows that struggling to get by is probably not your fault. Your family's financial squeeze is driven by cultural shifts and political decisions. Making life more livable again will require middle-class people getting past shame and starting a frank conversation about how to undo the worst of these harmful trends and policies.

What's the biggest change you think needs to happen to make being middle class in America affordable again?