Also, you need to consider how it is payed for. It does not just mean that everyone suddenly have an additional income on top of everything they used to have. Y

Also, you need to consider how it is payed for. It does not just mean that everyone suddenly have an additional income on top of everything they used to have. You now also have money circulating in the economy in new patterns. And you also have new taxation used to finance it. Taken together, this will impact prices and costs, and will drive inflation. The effect cannot easily be predicted. But looking at individual behaviour in a limited experiment where everything else stays the same does not cut it.