Laura, many thanks for this very interesting overview. While noting that I am an expert neither in UCTs nor tax policy, one initial thought that came to mind is the similarity between a UCT and a tax rebate, such as the earned income tax credit (EITC) in the US. Through the EITC, people earning low incomes are credited back a portion of the taxes they paid. This seems to me to be related to a UCT - there is the condition that you have to have earned an income, I suppose, but other than that the government is effectively giving people an unconditional transfer to spend however they'd like based on one poverty indicator (salary level). There is of course the difference that the tax credit was previously the individual's money in the first place; but come April 15 in the US, this still represents a transfer from government to individual. You mention relevant concerns raised about UCTs, such as whether people will use them productively; in terms of politically selling the idea of UCTs, perhaps the experience of these kind of tax rebate programs in developed economies could be considered.