Mortgage rates were little changed Tuesday following the release of weaker than expected economic data. Construction Spending fell unexpectedly by 0.9% in July. An increase of 0.5% had been forecast. The Institute for Supply Management manufacturing index experienced its sharpest drop in three years last month to 49.6. Readings below 50.0 indicate contraction in the manufacturing sector. Stocks moved lower. Rates may become increasingly volatile later this week, as the European Central Bank meets on Thursday to discuss additional aid measures to troubled European nations, and the most important economic data of the month, the Employment Report for August, will be released on Friday. No other key data will be released today.