If people can 'live' on that and continue to have kids and get that expanded to cover the kids...where is there any incentive to work?
All some people require is a couch, a TV, the Internet (pretty cheap), and food. Medical is already taken care of. :-\
Well, I'd propose to keep the income low, too low for a single person to live on their own - I see nothing wrong with 3,4,5, people sharing an apartment - I had two room-mates when I moved-out at 17, and we split everything, and ate & lived ... really cheap! Lot's of people with very low incomes live by sharing places or living with parents, friends, and relatives - when I bought my house & was single I rented-out my spare bedroom to help-out friends & pay my mortgage.
The idea is not to give someone enough to live a fully independent comfortable lifestyle, but just enough to keep them alive & off the streets. This might be something like $5-600/mo., as just a guess - I'm really not sure.
The idea is to NOT provide means-tested benefits for select groups (with all the fraud & disincentive that entails), BUT still have some rudimentary net so no one need be fully destitute on the streets (unless so chosen). That's why I took healthcare out of the equation (via single-payer).
I haven't given hard thought to kids, but I believe adding some additional percentage for minor children to be added to a resident supporting parent's base might be in order, as long as we don't incentify having kids on the base income alone (that's why it needs to be small)
Trust me, I'm open to ideas on this at the moment, because it strikes me as an interesting system. I though it was crazy when a buddy of mine first brought it up, but now I'm thinking it might have possibilities.
(I abhor means-tested social-systems)