Fine piece by economist Tim Harford. If I were still teaching MBAs I'd assign it to them. Has several interesting nuggets including these three:
Now there are 60-odd million in the world, nearly one for every 100 people - not bad for a humble bookcase. . . .
Every three seconds, another Billy bookcase rolls off the production line of the Gyllensvaans Mobler factory in Kattilstorp, a tiny village in southern Sweden. . . .
It does not look like it has changed much since 1978, yet it costs 30% less. That is partly due to constant, tiny tweaks in both product and production method.
UPDATE: Link included now.