The results are also a sign of the country's oversupply of retail space at a time when commerce is moving online, he added.
"On an apples-to-apples basis, we have twice as much per-capita retail space as any other place in the world. The U.K. is second. They're half of what we are. So, yes, we are the most over-stored place in the world," he told CNBC's "Squawk Box."
With the U.S. having an estimated 48 square feet of retail space per citizen, the footprint is poised to decline "pretty fast," Kniffen said.
In his view, about 400 of America's 1,100 enclosed malls will fail in the coming years. Of the survivors, about 250 will thrive and the rest will struggle. Likewise, Macy's probably needs 500 of its roughly 800 existing stores, he said.
He said the mall owners and operators most likely to come out on top are Taubman Centers, General Growth Partners and Simon Property Group.