WASHINGTON, DC—Government economists have been second-guessing the accuracy of the nation's GDP calculation and, in a recently-announced step, the Bureau of Economic Analysis said it will alter its methodology for the second quarter numbers. While this debate is fascinating and controversial for policy wonks, it has been of glancing interest to the business community.

The commercial real estate industry, though, might want to at least acquaint itself with what is happening as this change is likely to impact the monthly Construction Series at some point. This series includes Permits, Starts, Completions, Houses Sold, Construction Spending, Manufactured Homes Shipments and Placements, Houses For Sale, Under Construction, and Dealers' Inventory of Manufactured Homes.

Briefly, this is what has happened: a week ago, the Commerce Department's Bureau of Economic Analysis announced in a blog post it would be making changes in the way it seasonally adjusts data to calculate economic growth, starting with the initial second-quarter GDP estimate on July 30.

Specifically, the agency said that although it routinely adjusts its numbers for seasonal variations, such as a bad winter, growth in the first quarter has still been typically weaker than it should be compared to the other three quarters. There is still "residual seasonality" in its data -- in other words, it hasn't scrubbed these seasonal patterns completely out of its calculations.

Some of the areas it will be looking at include federal government defense services spending and certain inventory investment series. After the release of the second quarter GDP data, " BEA will continue looking at components of GDP to determine if there are opportunities to improve seasonal adjustment methodologies," it said in its blog post.

BEA didn't mention the construction data specifically but as other economists have noted, these figures highly sensitive to residual seasonality. An analysis by Barclays Chief US Economist Michael Gapen, for instance, came to that conclusion, according to the Financial Times.

The Financial Times wrote, citing the Barclays analysis:

"The boom in construction spending in the mid-2000s followed by the protracted crash in activity is difficult to smooth through and the period since 2010 is too short to provide a reliable sample for estimating seasonal factors on monthly data. In addition, more than most sectors, construction activity is adversely affected by severe weather events, which have occurred to varying degrees in the first quarter of each of the past two years."

Other studies, though, have not found significant residual seasonality, including an analysis by the Federal Reserve Bank in Washington DC. A separate report from the Federal Reserve Bank of San Francisco did find evidence of it and when it re-estimated first quarter GDP it found the economy expanded at a 1.8% annual rate -- not 0.2% as the BEA reported.

How policy makers at the Federal Reserve will interpret these conflicting studies remains to be seen.

And this is where the BEA's change to GDP calculation could have the greater impact on the commercial real estate industry. While the update to the Construction Series will presumably make it a more accurate indicator of the industry's health, the diverging view with the Fed family will make it harder to predict how the Fed will react to economic data.