[ninalanyon]

The money comes from taxation.

Another way of looking at UBI is simply as an adjustment to the tax system that shifts the baseline of the tax curve to that people with less than a certain income receive money instead of paying it. This probably works better in countries hat have a more nearly smoothly varying progressive tax rate than those like the UK which have just a few widely spaced thresholds.

Then it is simply a case of adjusting the parameters of a fairly simple formula so that the total tax revenue is as it was before and that the minimum after tax income is something one can live on.

The general idea is that in civilized countries you are paying out the money anyway, just less efficiently.

[mothballed]

Government expenditures are ~30% of GDP in US. Theoretically you could just distribute ~30% of the gdp/capita (about $28,000) to every person in the USA, make them buy all government services on the private market (government now gone except to collect and distribute the single UBI), and you'd not have much tax effect on productive enterprise (or alternatively, distribute ~20% or almost $20,000 and return to pre-1913 non-wartime government services).

[ninalanyon]

> make them buy all government services on the private market

The market won't magically provide all the services that people need. The government would have to have some mechanism that made sure that all the necessary services were available to everyone.