Federal workers whose jobs aren't deemed essential aren't allowed to do their jobs during the shutdown, even if they're willing to work for free. But what about the workers whose jobs are essential? That's your law enforcement, national security, air transportation, etc. stuff. Walking around today you might notice that despite the shutdown hype, life is basically going on as normal. That's because all those essential workers are still on the job. But they're not getting paid. If you're not essential, you aren't allowed to work even if you're willing to work without pay. If you are essential, you have to work even though you won't be paid.
Yet having prison guards and air traffic controllers work without pay clearly isn't a viable way of running the government in the long term.
One reader asked me how long we can keep providing essential services on this basis. The answer is that there is no answer: It can last a while, but not indefinitely. These are patriotic people who will keep doing their jobs, but they obviously can't work for free forever. Realistically, as a shutdown drags on there will be political pressure to appropriate funds to pay certain people. The president already signed an ad hoc bill that assures soldiers will get paid. Given a long enough shutdown, FBI agents and the people feeding the animals at the National Zoo might also get special bills for them. In practice, though, a fall 2013 government shutdown has a rather short potential lifespan. That's because even with the government shut down we're still going to breach the statutory debt ceiling around Oct. 17-20 at which point the lack of discretionary appropriations will be subsumed by a larger and more cataclysmic issue. That means we won't really get to find out what happens when you essentially personnel to work two months without salary.
My colleague Joshua Keating has been asking how we would cover the government shutdown if it were happening in a foreign country. I would say one aspect of that is that if a political crisis in a foreign country led to members of the regime's security apparatus not getting paid, we would expect that to precipitate a hard or soft coup d'état in which the security services decisively intervene in order to get thesmelves paid.