Giving away huge sums of money might not be so difficult when you've got billions of dollars, but it might be different for three New Jersey students who are pledging to give away a chunk of their income no matter how much or little they make over time.

Nick Beckstead, Mark Lee, and Tim Campbell, philosophy graduate students at Rutgers University, are this month launching a chapter of Giving What We Can, an initiative that began at Oxford University in England to encourage people in the developed world to pledge a fixed percentage...