Greenspan: Effective demand as weak as during Depression

"The fact that the market is anticipating that the Federal Reserve will raise interest rates, yet the yields on the 10- and 30-year Treasurys are falling is an indication of how weak the overall global economy is"

In fact, effective demand is extraordinarily weak, said former Fed Chairman Alan Greenspan told CNBC on Thursday..

"The way I measure it, it's probably tantamount to what we saw in the later stages of the Great Depression," Greenspan said in an interview with "Closing Bell."

That said, he acknowledged "it's not anywhere near what the problems were back then but we haven't seen anything like that since then."

Greenspan, who served as Fed chair from 1987 to 2006, also called the overall economic data for the United States "not strong." 

Read more: While the jobs growth has been very significant, there is evidence of weakened productivity: "That is a key statistic which tells how the economy is functioning."