Why should large construction companies pay attention to homebuilding data?

I have been reporting how the housing market is picking up steam.  The housing market is important to commercial construction because when you build homes, other structures tend to follow (schools, retail, hospitals, offices, etc.).  There's another reason why it's important to watch housing numbers:  homebuilding is a leading indicator for overall construction employment.  Take a look at the graph below:

Hopefully this uptick in housing starts is signaling that overall construction employment is about to improve (construction was disproportionately hammered during the recession, although it was also a part of the problem).  If employment rates improve, hopefully so will wages.  This could be particularly good news for my students seeking jobs!