> In the minds of most people it's more of a "you will not go hungry or get cold in the winter" level of support, and I would make the argument that the majority of folks would continue to work to supplement their income beyond the bare necessities.
And that's the essential fallacy: You cannot control the prices of goods and services in the market.
Once you provide a basic income to everybody, that will create a scenario wherein the majority of people benefit from the income inversely proportionally to their level of other income. This is the intended effect: The poor benefit the most and the upper-class are largely unaffected. So it's a good idea, right? Not exactly: What are the poor going to spend their income on? Primarily food, housing -- the "not going hungry or cold" things. So they've got more money to go out and buy food and they will. And the lower-middle-class who make a bit more than that will now have enough money to buy more food and better housing and they will. And the middle-middle class have a little extra money to spend as they wish and they will. And so on. But the majority of that money will be spent. With more free cash to go around, prices will rise to capture the additional profits. When prices go up we have inflation and now the poor are back to not being able to afford food and shelter and the lower-middle-class are back to living hand-to-mouth and so forth. The market compensates for the additional influx of cash by providing opportunities to soak it up, so it doesn't wind up helping anyone in the long run.
Well we'll just peg it to the rate of inflation and the problem will be solved, right? Again -- it's not that simple.
See, only one in three Americans is working. If we determine that each American needs about $500 per month to "not go hungry or cold" then that means the average American will have to pay $1,500 in additional taxes. We'll burden the upper class with the majority of those taxes, of course, but this isn't good for the middle class either. The upper-middle-class winds up being saddled with enough additional tax burden that they join the middle-middle class. And the middle-middle class who were previously getting along fine on a household income of $50,000 just joined the lower-middle class because even with the added income they have to pay more for the basics: food and shelter because of the additional inflation.
So now we're saddled with a shrinking middle class, (sound familiar?) nobody being able to afford any more than they were before and the rich continue to remain largely unaffected by all of this. In the end it accomplishes the exact opposite of what you set out to do.