Rapid recovery from the Great Recession + the shale oil boom has fueled demand for single-family home in TEXAS.  Tight inventories and rapid price appreciation is pushing prices UP  about 33% from  2007.  Nationwide rose only 2.8% during this same period.  Texas has enough land, but developing subdivisions is slow, so some builders are without lots to build on + labor & some material shortages.  All of these have gone up!  So declining affordability.