I doubt we are even near 500%, but I'll go ahead and say I think it's possible in the short term for California to be lose 500% of it's GDP. It's possible to borrow against our future, both literally with money, and figuratively by decreasing future productivity.

For instance, we're (probably) negatively impacting kids education, that's going to have a negative impact on the economy for the next 50+ years. If we fuck up the food supply chains too badly (e.g. migrant works, locusts in africa [1], etc) more kids will suffer from malnutrition, which has a long term effect. Increased poverty rates from the shutdown will likely increase crime rates (and have many other ill effects), which will have a long term effect. Putting the economy into a recession will no doubt significantly slow down all sorts of R&D work delaying useful (and even life saving) inventions. And so and and so forth.

https://arstechnica.com/science/2020/04/africas-huge-locust-...

Why would losing 500% of California's 2019 GDP be impossible? It's difficult to imagine, sure, but that's just 5x $2.7T.

The sheer number of n'th order effects of this crisis might just mean that most of the economic pain is in the long, fat tail spanning decades into the future.

Amortize that cost as irreversible economic damage and it might be implausible, sure, but not inconceivable.