It has been a truism of the American economy for decades: When oil prices rise, the economy suffers; when they fall, growth improves.<br />As oil prices have fallen to levels not seen since 2003 - sagging below $27 a barrel on Wednesday before rebounding to about $30 on Thursday - many experts now say they do not expect lower prices to bolster the domestic economy significantly in 2016.<br />Economists at JPMorgan Chase, who predicted last January that lower oil prices would add about 0.7 of a percentage point to the economic growth rate in 2015, now estimate that lower prices might have shaved 0.3 of a percentage point off the growth rate.
