I need AS MANY diverse respondents before Monday! Do me a favor and spread this far and wide... spam your family & friends for me!
Can't. S/he forgot one essential category for disposable income: savings. Sorry, but I think it's important.
I am afraid that that particular part of my survey was NOT well written, given that you are the third person to ask about it. Marketing is weird (and at least a little bit ACTUALLY evil).
In future I will try to make it clearer that what I MEAN by discretionary income is "the money you spend for fun"
Businesses don't want us to save, and marketing is the art of convincing people to spend all their money (then some more).