Even the most casual reader of financial and economic news knows that the speed of economic growth matters. Businesses―manufacturers, service providers, and retailers, among others―need to know so that they can decide how much to invest in new production facilities, how many people to employ, and what to stock on their shelves. Fiscal policymakers need to know so that they can estimate government revenue and expenditure. And monetary policymakers need to know so that they can adjust their policies in an effort to ensure low, stable inflation and strong, stable, and balance growth.

But, does it make sense for all of these people―firms, households and governments―to focus on fresh estimates of GDP? How much attention should we pay to any new number? That is, when the U.S. Bureau of Economic Analysis (BEA) announces that their initial estimate of growth for the quarter just ended is 2% or 3% or (as it was last week) 4%, what should we think?

While GDP was once a key cyclical indicator, its value has declined substantially. In this post, we highlight three reasons: timeliness, seasonal adjustment and revisions. Not surprisingly, in the era of big data, those who need information on growth are increasingly turning to more timely indicators customized to their needs….