GreenWeaver-I think that money income derived from investments is also another form of discretionary income.
Here you can choose to reinvest the earnings and expand your holdings or take the earnings and spend it how you wish.
I was recently reading that the countries that have the highest income per capita are Luxembourg, Bermuda, and the United States of America. Norway was just behind the United States.
The income per capita really measures the average salary of a person living in that country. The higher ranking countries tend to have people with a higher net worth income as well. This survey on income was created by the World Bank Organization.