Let's just say that, beginning on April 1st, we pulled out of the world economy and refused to trade with any other countries. Here's what would happen:
1. A run on all foreign goods. Prices would spike on, well, lots and lots of stuff.
2. Higher prices for remaining goods that are made in America. By the way, there's not a whole lot of that left.
3. Food prices would plummet, since our farms are excellent. But the GOP (to their absolute shame and discredit) would surely increase the sit-on-your-ass-and-be-lazy payme-- I mean, the farm subsidies, so prices would remain "fair" for farmers.
4. Gas prices would likely double. On the plus side, we might start drilling in ANWR sometime this century.
5. As prices remain high, the average consumer would have less and less free cash to go around. That means companies that market entertainment and/or luxuries would feel the squeeze. Eventually, the US would hit depression mode.
6. Since there is a lack of manufacturing plants in America, we'd have to start building more of them, then start manufacturing all of our own goods. That would take years to get going. But, even after we did all that, prices would still be sky high because of labor unions, and the fact that there would be little competition.