America’s consumer-price inflation stays above 5% in August

IT IS HARD to overstate the time that goes into calculating a consumer-price index. In America statisticians survey nearly 10,000 people every quarter, construct a sample of 80,000 things they buy, and then monitor their prices by ringing up thousands of shops, restaurants and offices. So the hard-working boffins might be miffed that the Federal Reserve thinks it wise simply to lop off the things with the biggest price swings. The result that emerges is known as “trimmed mean” inflation. With America facing its most sustained price pressure since 1990, this narrower measure is more than an academic exercise.