Because single-family construction activity is rising much too slowly while multifamily activity shrinks, housing inventory has declined Y-o-Y for 27 straight months, prices keep rising faster than wages, and affordability is at its lowest level since early 2009. As a result, housing sales have been flat for the past 12 months at an annual rate of about 5.5 million units, and Y-o-Y first-time mortgage application growth is barely positive.