Missouri was the first state to enforce a self-exclusion list, four years after it legalized riverboat gambling in 1992.

WSJ: States Rethink Gambling Limits

Lists "can help some people stay away, but for most people merely signing a self-exclusion list won't control that urge, " said Keith Whyte, executive director of the National Council on Problem Gambling.

WSJ: States Rethink Gambling Limits

"I think it's fair to say that the Web has great potential to at least mitigate everyday tendencies towards self-segregation and social exclusion, " Kaufman said.

CNN: Does class decide online social networks?

It is a miserable existence which can sap energy and self-confidence, it can lead to exclusion from mainstream society and ordinary pursuits, to alienation and to marginalisation.

BBC: Jackie Ballard: Principle into power

Other large tax expenditure provisions that I did not include in this experiment include the earned income tax credit, the child credit, the exclusion of employer provided and self-employed health benefits, and the present law treatment of various forms of retirement income and pension plans.

FORBES: Eliminating Tax Expenditures To Cut Rates - Early Results Are Underwhelming

Research shows that even a single instance of exclusion can undermine well-being, IQ test performance and self-control.

CNN: The importance of belonging