Why are people concerned about "stone age" when the events that could cause such a thing are so devastating that you really have a more serious problem at hand than being unable to watch a monkey on youtube drinking piss and read what Kim whatshername... Kardashigan(?) or some other uninteresting person is posting on Facebook about the color of her lipstick or whatever it is.
Something that would cause an instant "stone age" scenario, such as a nuclear detonation in the ionosphere (or rather, several of them) or a massive stellar event (solar flare, asteroid, whatever) plays sooooo much in a different league. You should be thinking about things like losing agricultural surface that nourishes millions or drinkable water (from e.g. fallout) or a crater the size of New England where your house used to be, and an earthquake like you've never seen before followed by 500 years of winter, or a radical change in the atmosphere or climate or seasons. Think of events as radical as "formation of the Panama isthmus" which changed the rules for everybody during a period of a hundred thousand years.
Besides, the idea of "blasting a nation (or mankind) back to stone age" is totally silly. You can kill all reasonably modern electronic devices which aren't hardened or in a bunker relatively easily. But you can't prevent people from rebuilding them or buying replacements from another location on the globe. You can erase a great deal of information that is stored on digital media, but you won't be able to erase all (there's fortified underground archives for that exact reason), and you can't erase what's in people's heads (short of killing them).
Would it hurt the economy? Surely. Would it cause Mad-Max-like conditions with bands of rednecks looting and robbing? Possibly, even likely, especially in the Land of the Free. But it wouldn't be "stone age".