Here’s one key takeaway from the Commerce Department’s report Monday on U.S. construction spending. The

0.4 percent decrease in November, which itself was weaker than the most pessimistic Bloomberg survey forecast, was accompanied by downward revisions to prior months. The combination suggests some economists may revise down their fourth-quarter GDP tracking forecasts.

* October construction spending rose 0.3 percent, compared with a prior estimate of 1 percent, while September outlays advanced 0.2 percent versus a previous estimate of a 0.6 percent gain