For a very unsettling demonstration of statistics being easily biased to whatever result you like, go to this blog by science journalist Christie Aschwanden and chart maker Richie King. Scroll down to the Hack Your Way To Scientific Glory control panel. There you can play your hunches as to how Democrats versus Republicans affect the U.S. economy. With a few changes in how you define the factors and measure the response, the results can be manipulated as you like. Print out the final statistics and use them to beat up your political opponents. What fun!