PIMCO’s Mohamed El-Erian says the U.S. economy is improving, but still has big issues to deal with. “We continue to heal … but we’re not at escape velocity,” El-Erian tells CNBC. He says that while improvement can be seen in areas like housing, the U.S. hasn’t gotten over “the three big issues”: not enough aggregate demand, too few structural reforms, and too much leverage (which has been shifted from the private sector to the public sector). El-Erian says he thinks Treasury yields may actually fall in the next few months, but he thinks that the long-term environment is one of rising rates. He also says the Federal Reserve’s economic growth projections are too high.