By: Mark Glennon*   A research report recently issued by Nuveen Asset Management provides another take on the total annual liability Chicago taxpayers would face if they properly funded pensions for the city’s overlapping layers of government. Brace yourself.   Chicago has been contributing to its pensions only about one-forth of what Nuveen calls Annual Pension Cost — “the amount determined by actuaries to keep the plans solvent.” (We note that S&P recently said essentially the same thing.) The unpaid portion of the city’s pension contribution exceeded $1.2 billion, “a figure representing an astonishing 43% of the city’s general