Since the 1989 cult classic Groundhog Day never specifies exactly how long it took Bill Murray’s character to escape his repetitive purgatory in Punxsutawney, Pennsylvania, fans devoted enough to run the numbers have come up with their own estimate: 33 years. Players in the US housing market hope to escape the numbers-driven winter of their discontent quite a bit sooner, but green shoots are sparse so far and last week didn’t do much to help. The nation’s largest homebuilder, D.R. Horton, saw its proverb ...