GDP

What it measures

Gross domestic product adds up everything produced in the country in a quarter: what households buy, what businesses invest, what governments spend, and exports minus imports. The Bureau of Economic Analysis publishes it about four weeks after the quarter ends, at 8:30 AM Eastern. That first release is the advance estimate; second and third estimates follow a month apart as more data arrives, and the whole history gets revised every summer.

Reading the rate

The headline number is real growth, adjusted for inflation, at a seasonally adjusted annualized rate. A quarter in which the economy grew half a percent is reported as roughly 2 percent, because that is what it would add up to over a year at that pace. It makes quarters comparable, but it also magnifies noise: a swing in inventories or trade can add or subtract a full percentage point in a single quarter without saying much about the trend.

Consumer spending is about two thirds of GDP, so retail sales and the monthly income and spending data are the best previews. Trend growth in the United States has been somewhere around 2 percent a year, so a 3 percent quarter is strong and a negative quarter is a warning, though one negative quarter is not a recession on its own.

Why the advance estimate is the print

By the time the second and third estimates come out, markets have moved on. The advance estimate is the one everyone waits for, and it is the one Mini Macro scores. Revisions can be large, but the game uses the first published number for every indicator, so nobody gets rescored months later.