The nearest real life analogy to Rand's "Going Galt" is when the garbagemen go on strike. That's when the world panics.
The busses go on strike and the people take cabs or subways and vice versa. The hospitals go on strike and the death rate can actually go down because fewer people with communicable diseases are swarming the hospitals. The cops go on strike and people go to work earlier, leave earlier and avoid late hours when the criminals are most active.
But the garbagemen go on strike and the city has about four days, max, before it really, really hurts.