Does voting by mail increase voter turnout?

Does voting by mail increase voter turnout?Look at the 2012 voter turnout statistics for the states of Oregon and Washington, both of which now exclusively utilize mail-in voting, and compare the turnout statistics with two states that do not exclusively utilize mail-in voting. You may use the Voting and Registration data from the U.S. Census Web site (linked in the Resources) or another comparable source. Should states use mail-in voting instead of the traditional ballot process? Provide two specific reasons for your arguments.