As policy makers globally prepare to cut borrowing costs again, banks around the world are feeling the heat. Rock-bottom interest rates can help stoke growth, but they also put the squeeze on lending margins. Big U.S. banks including JPMorgan Chase & Co. and Citigroup Inc., which reported second-quarter earnings last week, are already seeing the revenue impact of declining interest rates -- even before the Federal Reserve delivers a cut expected at the end of the month. Their European and Japanese peers, which release their results in the next three weeks, are likely to struggle with the same issue. And they’ll be ... (full story)