FOR the world’s largest economy, 2015 has been a series of disappointments. In March builders began construction on just 944,000 new homes, well short of the million or more that had been expected. In April the number of people out of work and claiming benefits exceeded economists’ predictions. And on May 29th official data, which had previously suggested the economy had grown by 0.2% at an annualized rate in the first quarter, were revised to show a contraction of 0.7%. Consumption slowed, investment slid 2.8% and exports dropped by 7.6%.

America still accounts for 23% of the world’s output, so a sustained slowdown would have global impact. Happily, most economists offer a comforting explanation: this is all temporary. Start with America’s dreadful weather. Though this year escaped the “polar vortex” (the weather system that dragged down temperatures and output in 2014), it was bitterly cold. Thermometers showed record lows in many eastern cities in February. With streets so icy and air so cold it is no wonder consumption expanded at just 1.8% at an annualized rate, much lower than the 4.4% of the previous quarter.

A simple analysis by Aneta Markowska of Société Générale, a French bank, tracks the correlation between anomalous temperatures and GDP. It suggests that the freeze lowered first-quarter growth by around 1.9 percentage points. The good news, she argues, is that the trend should reverse with improving weather.

Oil markets, boiling last summer, have cooled too. In the second half of 2014, the price of America’s benchmark crude, WTI, dropped from $106 a barrel to below $60. With the reward for finding oil falling sharply, the amount spent searching for it and extracting it has tumbled too. According to data from Baker Hughes, a firm that provides services to oil companies, the number of rigs drilling for oil fell from 1,866 a year ago to 875 on May 29th.

With time, cheap oil should help the economy, by leaving consumers with more to spend on other things. At the start of June petrol (gasoline) prices were $2.67 a gallon, nearly a dollar cheaper than a year ago. Some shoppers, fearful that they would soon rise again, may initially have saved this windfall. But inflation has now disappeared for goods like food, which cost a lot to transport and so are affected by energy prices. As the benefit of cheaper oil feeds through the supply chain, the increase in income may seem more permanent, and so spur spending.

America’s anemic exports may gain strength too. Millions of tons of petroleum products and chemicals are shipped out through the ports of Los Angeles and Long Beach each year. A strike sapped activity at both by more than 3% in the first quarter. With the dispute resolved, they are now exporting record amounts. The exchange rate may help. The dollar rose by almost 9% in trade-weighted terms in the second half of 2014, as the American economy strengthened, making exports more expensive for foreigners to buy. That run-up has since reversed, with the greenback down 2% since March.
Those who believe that the economy’s contraction is a blip also advance an even simpler argument. Whatever the reason, since the onset of the subprime crisis in 2007, the first quarter has consistently been a bit of a dud. The average outcome has been a contraction; even in the best first quarter of late (that of 2013), the economy grew by only 2.7% on an annualized basis (see chart). That logic, and the host of temporary factors hitting consumption, investment and exports, suggests much more can be expected from the second quarter. If it too is a disappointment, optimists will find the news much harder to shrug off.

From the print edition: Finance and economics