Affordability is a 'defining challenge' for Americans, with food costs leading the way, report finds

Affordability is the "defining challenge" when it comes to economic mobility, according to a new report by the McKinsey Institute for Economic Mobility and the W.K. Kellogg Foundation.

The survey of 30,000 Americans across income levels found that 90% of those polled cited groceries and food prices as a top cost concern, even over other key expenses, such as housing and healthcare.