WASHINGTON (AFP) - The dramatic decline in global oil prices is good for the US economy, as consumers gain extra dollars to boost spending, Federal Reserve chairman Janet Yellen said Wednesday.

"From the standpoint of the United States and the US outlook... the decline we have seen in oil prices is likely to be on net a positive," Yellen said at a news conference after a two-day policy meeting, likening the drop for consumers to "a tax cut that boosts their spending power."