Nearly two percent of America is grassy green. Sure, lawns are beautiful and useful and they smell great. But are the costs — financial, environmental and otherwise — worth the benefits?

Cecilia Rouse, the chair of the White House Council of Economic Advisors, is as cold-blooded as any economist. But she admits that her profession would do well to focus on policy that actually helps people. Rouse explains why President Biden wants to spend trillions of dollars to reshape the economy, and why — as the first Black chair of the C.E.A. — she has a good idea of what needs fixing.