Member-only story
How to Measure Your Productivity
According to Science
You finish a day exhausted and assume it was a good one. It’s probably the worst measuring tool you own.
Hours don’t buy what you think
In 2014 the Stanford economist John Pencavel dug up records from British munitions factories in the First World War. A government committee had logged hours and output for workers, most of them women. Output rose with hours up to about 49 a week, then rose more slowly. At 70 hours it was barely different from output at 56 (Pencavel, 2014; The Economist, 2014). Fourteen extra hours bought almost nothing.
It’s a century-old dataset from a fuze-making floor, so don’t treat it as a law of nature. It does suggest that time at the desk and work done drift apart sooner than we assume.
You can’t trust the feeling
Sleep is the cleanest example. In a 2003 lab experiment, researchers kept people in bed for 4, 6 or 8 hours a night for…
