One thing at a time, please
ByTim Harford
The result was fascinating: on the multitasking runs, people were perfectly good at making predictions on the fly, but couldn't then explain the underlying patterns, or apply them flexibly in other contexts. The technical term for this is that their "declarative learning" was stunted by the distraction. In short, multitaskers seem competent at the time but may not be taking much away from their experiences.I try hard not to make that mistake. Even the twin monitors are designed so that while I'm reading a research paper on screen, this column stays in view.
But I am guilty of an entirely different form of multitasking: in any given month, I have lots of projects on the go. This feels a world away from distracting myself with instant messaging. In fact it feels symptomatic of being a grown-up in the 21st century. But perhaps it, too, is unhelpful.
The psychologists' lab isn't well-suited to testing that hypothesis, but there is a new working paper from three economists, Decio Coviello, Andrea Ichino and Nicola Persico. They studied the caseload of 31 judges in a specialised court in Milan, who over five years dealt with over 58,000 cases. Because of the way cases are randomly assigned, and a rule stating that cases must open no later than 60 days after assignment, some judges find themselves with many more cases open at the same time. Coviello and his colleagues find that judges who have been obliged to work on many cases in parallel take longer to complete similar portfolios of cases. One implication is that the 60-day rule probably slows the average case down rather than speeding it up.
The message for the rest of us is that Publilius Syrus was right about multitasking. One thing at a time is best. The exception, I suppose, is if you'd rather not remember what you're supposed to be doing. No wonder so many of us check our BlackBerries in meetings.
Tim Harford's latest book is 'Dear Undercover Economist' (Little, Brown)
