Treasury might not be able to stop payments after default even if it wanted to

Reuters has a fantastic story this evening on the impossible quandary facing Treasury officials should the unthinkable come to pass; purely as a practical matter, it’s far from clear that it’s even possible to stop making the 3 million payments that Treasury makes automatically every day. Doing so involves a massive computer-reprogramming effort which I’m sure could not be implemented overnight — and for political reasons nobody is going to get started on such an effort until after all hope is lost for a deal in Congress.

Realistically, then, the government is likely to breach the current debt ceiling no matter what Congress agrees. A failure to lift it would be a bit like an edict to a steaming supertanker that it had to stop dead: no matter how much force of law that edict has, sheer momentum is going force many basic operations of the public fisc to continue for some period of days or weeks.