Flashes of illumination rather than fireworks are expected at this week’s annual meeting of top central bankers and economists in Jackson Hole, Wyoming. Few predict anything so momentous as the speech by Federal Reserve chairman Ben Bernanke two years ago that paved the way for an unprecedented $85 billion per month stimulus plan. The spotlight will be on Janet Yellen, who will speak on Friday in her first appearance at Jackson Hole as Fed chair. “I don’t think she’s going to go anywhere close to monetary policy,” said Stephen Lewis, chief economist at ADM Investor Services.