Markets are anxiously awaiting Fed Chair Janet Yellen's speech Friday but Fed watchers say those looking for a clear sign of whether a rate hike will happen in September may be disappointed. "Federal Reserve chairs are often inclined to use the Jackson Hole event to preview monetary policy," PNC Chief Economist Stuart Hoffman and PNC Deputy Chief Economist Gus Faucher wrote in a research note Wednesday. But with the next Federal Open Market Committee meeting set for Sept. 20-21, still a month away, "Yellen is unlikely to use her Jackson Hole talk to signal an increase in the federal funds rate at the FOMC's next ... (full story)