You can add Harvard University economist Martin Feldstein to the growing list of experts who are worried about a double-dip recession.

“I would say there’s still a significant risk, maybe one chance in three, that there will be a double dip, real GDP falling, before we’re in the clear,” Feldstein, a top economic official in the Reagan administration and now a member of the committee that dates the beginning and end of recessions, told Bloomberg.

Second-quarter GDP growth was recently revised down to 1.6 percent from the initial estimate of 2.4 percent, and many economists worry that growth could slip further in the months ahead.

“We see a weak economy,” Feldstein said. “We see a fragile economy that is growing at a slower pace.”

If another slump comes, he appears to view that as one extended recession, rather than as two separate ones.

“If the economy turns down again, we would still be in recession, but that remains to be seen.”

Nobel laureate economist Joseph Stiglitz says the economy may remain down in the dumps for a while and that we need another dose of fiscal stimulus to turn things around.

“There are many ways in which you can see us almost surely being in a Japan-style malaise,” he told The New York Times. “It’s just really hard to see what will bring us out.”