He said PMI doesn't know how long this plateau will last. (cnbc.com)
In cycle 24, we indeed observed such a scenario, with two peaks separated by a particularly long plateau, lasting 18 months from early 2012 to mid-2013 (see graphic). (sidc.be)
They found a long plateau in people's 40s and 50s when the ability to correctly identify emotions based only on the eyes was strongest. (businessinsider.com)