Why Didn't More People Leave?

Why didn't more people get out of New Orleans before Hurricane Katrina demonlished the city? A lot of people are mad right now that 100% of the people were not evacuated? But is that even possible? And how costly would that be?

You don't need to under-estimate the devastation or its probability of coming true to have made a rational choice to stay. For some, the costs probably out-weighed the benefits of leaving. We would expect it to be relatively more costsly for the poor to get out than the wealthy. And surprise, the poor seem to be disproportionately affected.

There might be a fair criticism of the city or state government for poor preparation or how they have handled it since. Knowing the incentives people have (ie knowing that a large population wouldn't choose to leave the city) would have made it possible for planners to try to change those incentives.

But perhaps the governments' actions were rational too. What were the costs of ordering a mass evacuation and what was the probability that nothing so serve would end up happening? Perhaps all the choices involed were probablistically correct and we just ended up getting unlucky?

All this reminds me of playing poker.