Saturday, 15 February 2014

Unintended Consequences....

Fascinaing FT article giving examples of how, even with the best intentions, providing too much information can have unintended adverse consequences...

Traffic Light countdowns
Turns out that this story is reported much more comprehensively in than in the Financial Times ! Who'd have thunk it? But anyway:

A number of cities around the world have pedestrian crossings that give a "countdown" of how many seconds are left until the "green man" turns red, and Toronto joined the club when it began installing the countdown signals across the city.

When economists Sacha Kapoor and Arvind Magesan examined the data they found that, surprisingly, the new signals caused MORE accidents between cars, especially rear-end collisions, and suggested that this was due to drivers being able to see the countdown timer - some drivers then slowing down while others accelerated in the hope of making it through before the timer hit zero.

Heart Operation Report Cards
The FT article also reported on a study (here) by David Dranove, Daniel Kessler, Mark McClellan and Mark Satterthwaite which assessed the "report cards" used in two US states to report on the success rates of doctors and hospitals.

Focussing on the reports for cardiac surgery, the researchers found that the fact the sucesss data was to be published meant that hospitals now had a powerful incentive to only operate on those patients most likely to survive - so patients with complicated problems became more likely to have their surgery postponed.

End result : More people died of heart attacks.

As the authors say in their report :
"We conclude that,at least in the short run, these report cards decreased patient and social welfare."