The article looks at the Opportunity Card program in the United Kingdom. Parents try it often: more pocket money for good behaviour, less for bad. Now the British government wants to introduce a similar scheme for the nation's teenagers. From 2008, it proposes that everyone aged between thirteen and nineteen should have an Opportunity Card, loaded with £12 ($21) worth of credits. Those from poor backgrounds and engaged in useful activity (such as voluntary work, or attending school regularly) will get more credits, perhaps another £12 per month. Those who misbehave (through truancy, vandalism and the like) will get fewer, or none. The credits will be redeemable for sessions at sports centres, dancing lessons and other worthy pastimes. This is a prime example of the government's favourite approach to public policy: interventionist, but delivered through a market mechanism. It sounds tempting, benefiting both the participants and, by keeping them out of trouble, everyone else too. The government cites academic research that shows a correlation between inactivity and misbehaviour. Healthy hobbies such as sport, art and music, by contrast, give young people a sense of purpose. But there are flaws. If the incentive for good deeds mutates into a mere "payment", it risks blunting goodwill.