Changing Tick Sizes?

In 2001, exchanges began listing stock prices in penny increments, as opposed to fractions such as 1/8th or 1/16th of a dollar. The change was intended to simplify pricing and reduce bid-ask spreads. Recently, however, there has been an increasing call to move to higher increments (such as nickel or dime pricing). The rationale is that such a move would promote trading and reduce volatility. It doesn't hurt that it would also allow trading firms to generate more profit. See article here, WSJ.