Computers outperform humans on GDP forecast
Recession worries: Workers are seen installing a battery onto an electric vehicle in Michigan. The US economy contracted for a second straight quarter, with GDP falling at a 0.9% annualised rate from the first three months of the year. — Reuters皇冠投注网址（www.hg108.vip）是皇冠体育官网线上直营平台。皇冠投注网址面向亚太地区招募代理，开放皇冠信用网代理申请、皇冠现金网代理会员开户等业务。皇冠投注网址可下载皇冠官方APP，皇冠APP包括皇冠体育最新代理登录线路、皇冠体育最新会员登录线路。
NEED to gain a sense of where US economic growth is now and where it is likely to be in the future?
It might be better to look at calls from largely automated computer models rather than economists, judging by estimates of second-quarter gross domestic product (GDP) ahead of the acutal results released Thursday.
The US economy contracted for a second straight quarter, with GDP falling at a 0.9% annualised rate from the first three months of the year, the Commerce Department’s preliminary estimate showed.
The median estimate in a Bloomberg survey was for expansion of 0.4%, and of the 74 projections by economists, 23 were for a decline.
Forecasts in so-called “nowcast” models, however, were closer to the outcome. The Federal Reserve (Fed) Bank of Atlanta’s GDPNow index, for example, saw a 1.2% decline.
Another similar computer model scored a direct hit: The estimate from S&P Global Market Intelligence, initially conceived by Monetary Policy Analytics Inc – co-founded by former Fed governor Larry Meyer – predicted a 0.9% second-quarter contraction.
Its clients include governments, banks and the Fed itself, which uses the data to glean insight on where the economy is going.
The latest GDP report was closely watched, given that two consecutive quarters of shrinkage is one rule of thumb that many use to gauge whether an economy is in a recession.,
The official determination of ends and beginnings of business cycles is made by a group of academics at the National Bureau of Economic Research.
Nowcast gauges have gained bigger followings as their accuracy improves, and the estimates they produce hew more closely to outcomes as they accumulate data.
GDPNow, for instance, had forecast a 1.8% decline earlier in the week, but adjusted to reflect the 1.2% drop by Wednesday.
The S&P model produces projections that are within about 1.2 percentage points of actual GDP about three months before the Bureau of Economic Analysis (BEA) release, with the gap narrowing to about half a percentage point closer to the release date, said Ben Herzon, an executive director at the firm.
We use the “bean-counter method,” said Herzon. “What we do is look at the BEA source data and replicate their methodology.”
The trick is estimating values for the latest month of data that haven’t yet been publicly released, he said.
The Atlanta Fed’s GDPNow model is largely publicly available and also mimics the methods used by the BEA to estimate real GDP growth.
One key difference is that it isn’t subject to judgmental adjustments.
“The average absolute error of final GDPNow forecasts is 0.84 percentage point,” according to the Atlanta Fed, which emphasises that the result isn’t an official forecast by the bank, its president, the Fed system, or the Federal Open Market Committee.