If you are 65 or older, you get to ride the NYC subways for half price.
I ask why? Don't old people get free money from the government in the form of Social Security, as well as other goodies like Medicare? Old people probably have more money most younger New Yorkers. They should pay their full fare just like everybody else!
In addition to the money they don't pay, the reduced fare program also costs the MTA additional money in administrative overhead. And surely some people will try to cheat the system by pretending to be 65 when they aren't.
Everyone should pay full price for the subways, with no exceptions.
I wrote a followup post responding to comments.