The result could be one of the biggest transfers of wealth in history, potentially reshaping everything from talks over Iran’s nuclear program to the Federal Reserve’s policies to further rejuvenate the U.S. economy.

The price of oil has declined about 40 percent since its peak in mid-June and plunged last week after the Organization of the Petroleum Exporting Countries voted to continue to pump at the same rate. That continued a trend driven by a weak global economy and expanding U.S. domestic energy supplies.

The question facing investors, companies and policymakers is how low oil prices will go — and for how long. Every day, American motorists are saving $630 million on gasoline compared with what they paid at June prices, and they would get a $230 billion windfall if prices were to stay this low for a year. The vast majority of that will flow into the economy, with lower-income households living on tight budgets likely to use money not otherwise spent on gas to buy groceries, clothing and other staples.

More: As Oil Prices Plunge, Wide-Ranging Effects for Consumers and the Global Economy