By a nudge we mean anything that influences our choices. A school cafeteria might try to nudge kids toward good diets by putting the healthiest foods at front. We think that it's time for institutions, including government, to become much more user-friendly by enlisting the science of choice to make life easier for people and by gentling nudging them in directions that will make their lives better.
"Most people know they should save money, but many don’t save enough and may not even be sure what amount is enough. Most savings advice goes against human nature and asks people to make complex calculations. To help people save, nudge them. When it is time for employees to enroll in your firm’s retirement plan, make signing up the default. People can choose not to sign up or can quit any time, but inertia and the status quo conspire to keep them from doing what’s good for them. Try a “Save More Tomorrow” program that “invites participants to commit themselves in advance to a series of [savings account] contribution increases” as their wages rise. This approach recognizes that people fear loss, and may perceive savings as a loss of disposable income, so it links increases in their savings rate to parallel increases in their salaries. When people earn more, the company automatically deducts more in savings. They don’t have to decide to save."
Set up choices in a way that takes advantage of how humans make decisions. You can nudge people in beneficial directions. To facilitate better decisions, design a default option that benefits people unless they explicitly choose otherwise.
[1] http://www.amazon.com/Nudge-Improving-Decisions-Health-Happi...
http://en.wikipedia.org/wiki/Nudge_(book)
quick summary - http://www.slideshare.net/sgmitch/nudge09