It’s deja vu time all over again for the world economy. That means you can expect output to pick up after a disappointingly sluggish first quarter, say economists at JPMorgan Chase & Co. and Capital Economics Ltd., Bloomberg reported. Since 2010, global growth has averaged 2.8% in the first quarter, compared to an overall rate of 3%, according to JPMorgan. This year, the expansion was just 1.7% — almost a percentage point below what the New York-based bank predicted at the start of the year and down from the 3.1% of the second half of 2014. “We have a forecast of a rebound in growth in the second quarter,” said Bruce Kasman, JPMorgan’s chief economist.