Before I ask for a drumroll and reveal “the secrets” of fighting poverty, a bit of background:

For a quarter-century after World War II, the United States made great progress against poverty. Then in the 1970s, we fumbled. Over the last 35 years, our economy has almost tripled in size, but, according to the United States Census Bureau, the number of Americans living below the poverty line has been stuck at roughly 1 in 8.

One reason is that wages for blue-collar and other ordinary workers peaked in the early 1970s, after adjusting for inflation, according to the Bureau of Labor Statistics. A second is the breakdown in the family and the explosion in single-parent households. A third is the quintupling of incarceration rates beginning in 1970, making it harder for impoverished young men to play a role in families or get decent jobs.

When those factors converge  a young woman with a 10th-grade education trying to raise a couple of kids as a single parent  poverty proves almost inescapable. Often the cycle is transmitted from generation to generation.

Still, there’s a reason for hope: We’re getting a much better handle on what policies can overcome poverty. We’re now seeing more experiments, modeled after randomized drug trials, that measure carefully whether an approach works and how cost-effective it is. Partly this reflects the rise of economists (at the expense of political scientists and do-gooders) and the rigor they pack in their briefcases.