Several other Financial groups have challenged National Cities evaluation procedure.
National City took what todays prices are and compared them to what prices were and their long term rates of appreciation have historically been.. in engineering we call that "french curving"... attempting to extrapolate future data points. Really a very poor way to evaluate real estate or any other market.
National City failed to even consider the effects of the Baby Boomer generation, the migration to warmer locations of businesses and people, the failure of the "rust belt" industrial areas, improving and deteriorating infrastructures of different locations, evolution of smaller businesses as a base of local jobs and economy.
A simple french curve approach may make for good reading... but it is over all unrealistic.