As the country’s economy recovers from the Great Recession, we keep hearing about a persistent negative theme: income inequality is worse than ever. The wealth gap is growing. The rich are getting richer and the poor are getting poorer. It is sure to be a talking point from 2016 presidential candidates.

David Madland says that the wealth gap is no accidental side effect from an economic policy antidote. In fact, it’s a cornerstone of the economic theory we’ve been operating under for three decades. He will speak at Politics and Prose this Friday, July 24th at 7 p.m. about his new book on the topic, Hollowed Out: Why the Economy Doesn’t Work without a Strong Middle Class (University of California, $28).

Madland says that supply-side economics relies on the rich to get richer, often through deregulation and tax breaks, in order for their wealth to “trickle down” to other groups. Though this has been the our economic policy of choice since the Reagan era, Madland breaks down each of the ways in which it’s completely failing us.

Instead, he writes, we must understand and focus on the benefits of a strong middle class, where wealth and opportunity can trickle “middle-out.” Research continues to show that when the middle class thrives, four crucial things happen in a society: trust among people is higher (necessary for doing business), governance is more balanced, consumer demand is more stable, and human capital develops.

Each of these concepts gets it own chapter in Hollowed Out, explained clearly and with historical context and real-time examples. In the meantime, Madland emphasizes how supply-side economics, and trickle-down logic, has stifled all of these things and led to inequality and recessions.

As next steps, Madland points out potential measures we can take to shift American economic policy, close the inequality gap, and improve the economy.

Madland is the managing director of the economic policy team at the Center for American Progress, and he has written extensively about the economy and American politics.

The event is free and open to the public.