How to get the clearest picture of who is poor in America?

That’s a question poverty experts have grappled with for years – and years. At last, the Census Bureau is updating how it measures who’s poor and who’s not – aka the poverty line.

Until this month, the poverty line has been calculated the same way for half a century. It was developed in 1964 as part of Lyndon Johnson’s War on Poverty. Ever since, a debate has ensued about how to determine who’s truly poor.

What’s the controversy? For starters, the original poverty line is pegged to only one thing: food costs as a share of annual income. But now, the Census Bureau will count other factors that might drive people into poverty, says Tim Smeeding, director of the Institute for Research and Poverty at the University of Wisconsin-Madison. These include, say, medical expenses and the higher rents in Manhattan versus Memphis. It also will take into account what the US government provides people to fight poverty, including food stamps, public housing, and refundable tax credits, Mr. Smeeding adds