'Zombie' Buyers Threaten 'Consumer is Back' Meme: Economist

Not unlike the popular "Walking Dead" television show, cash-strapped American consumers are half alive and barely able to make ends meet, economist Stephen Roach told CNBC on Friday.

"Japan had its zombie corporations; we have zombie consumers," Roach told CNBC's "Squawk Box". The Yale University lecturer and former Morgan Stanley chief economist pushed back against the idea that U.S. buyers have recovered from the 2008 crisis.

"The next time somebody comes on your show and says, 'yeah, the American Consumer is back,' ask them to try to justify that against ... one number: Five years of consumption growth, in real terms, of less than one percent a year," Roach said.

(Read More: Consumer Mood Sours as Fears About Jobs Rise)

Friday's soft-looking economic data supported Roach's thesis. The latest reading on consumer sentiment, which fell to a nine-month low in April; retail sales showed another contraction in March, following last week's report on weaker job growth for last month.

(Read More: Retail Sales Slump in March; Shoppers Stay Home)

"You pick the consumer apart quarter-by-quarter, you have two phases of the five-year slump I'm talking about," said the economist, who in his heyday earned a name as one of Wall Street's most relentless bears. "It was an unprecedented decline in consumer demand."

Roach added: "Normally you get a big snap back after that. [But] we have only had 2 percent growth in the following three and a half years," he said. "So that's a very anemic rebound from a horrific down turn."

By CNBC's Matthew J. Belvedere; Follow him on Twitter @Matt_SquawkCNBC