The cobra effect?

The odd-even formula for private vehicles in Delhi is making headlines every day; a Kotak Institutional Equities report has added a serpentine angle. Pointing out that barring vehicles with certain number plates from plying on certain days of the week could magnify the problem of more vehicles and air pollution, the report has warned against what it calls the "cobra effect".

Quoting a Freakonomics podcast, the report says that 150 years ago, the British government of the time used to award a bounty to those who brought in cobra skin - to prove that they had killed a cobra. Soon cobra farms cropped up and people started rearing cobras to claim the bounty.

Once the bounty was stopped - after the farms were unearthed - the cobra farmers simply released the snakes, which worsened the problem. Like those cobra farmers, many Delhi residents can potentially make light of the odd-even rule by simply buying vehicles with an even number plate if they own one with an odd number plate and vice-versa. Which means, more cars in Delhi.