Commentary  Recent home mortgage rate hikes have created concerns over the outlook for the housing market as well as the economy.  Housing sales are highly sensitive to interest rates.  A downturn in housing starts is among the earliest and most reliable indications of a downturn in the overall economy. Adding to this concern for homebuilding is the latest report from the Mortgage Bankers’ Association.  The Association’s January Mortgage Credit Availability Index (MCAI) fell to a level of 125, close to its average of the past two years.  The decline is attributed to lenders tightening their lending standards, particularly for borrowers with high loan-to-value ratios and those with lower credit scores. The MCAI is highly volatile.  It’s up 25 percent from its base year of 2012, but down from 185, where it was prior to the COVID-19 lockdown.  Will the combination of higher mortgage rates and a tightening of credit standards …