Despite showing resilient earnings, Chinese banks continue to struggle with non-performing loans and net interest margins, and their seemingly strong balance sheets belie problems down the road, write Citi Equities researchers Simon Ho and Paddy Ran. Chinese banks: Net interest margin “In one of the most homogenous set of earnings we have seen for the sector, most banks reported 12-13% earnings growth,” write Ho and Ran. Net interest margins were stable for big banks and only slightly down for small banks. Fee income was solid across the board, up 20 percent and 40 percent annually for large and small banks…