We begin with the biggest economic news today, for the american family budget. The price of gasoline is plunging. An announcement so dramatic, the experts are calling it the gas crash. Late this afternoon, this is what the department of energy said. The average price of a gallon of gasoline has dropped 50 cents, in just two months. Today, the average is $3.35 and it could drop even more before new year's. Abc's sharyn alfonsi is here to tell us how much and why. Reporter: It is the type of crash motorists love. Gas prices plummeting. At pumps in boston, $3.59, atlanta $3.79, salt lake $3.40 and l.A.3.68. The trip home for the holidays just got a lot cheaper. I'm thrilled! I mean, I have to buy gas no matter what, the fact that it costs a little bit less with christmas coming up. Reporter: Prices began rebounding after the refinery problems were fixed. Add to that, demand for gasoline down for winter. Analyst now think gas prices could fall even further before new years eve. We should have prices between $3.20 cents per gallon and $3.40 per gallon. Reporter: The good news comes on the heels of a game-changing headline from the internal energy agency. They predict the u.S. Will be energy independent by 2030. And become the world's largest exporter of oil, surpassing, counties like saudi arabia, venezuela, nigeria and even iran. Solar, wind and a backyard oil boom has changed the global landscape, and the landscape on our own backyards. We saw it first hand in kansas. New technologies unearthing previously untapped oil reserves there and across the u.S. The effects already being felt well beyond the gas pump. This unconvention revolution in oil and natural gas is already having a big impact on the united states. It has created something like 1.7 million jobs in the last few years. Reporter: And consider this. The economists at moodies tell us if gas prices drop another 50 cents this year, it will create another 350,000 jobs by this time next year. And in the next few months, pending no major disruptions, we could seal our grocery bills and the cost of medicine, many of them made out of petroleum, come down, too. Sharyn alfonsi, thank you so much.