It was 2500 families and encompassed about 10000 pretty much the whole town in some way and was over 4 years. The place was picked because at that time it was bit remote and somewhat isolated on that external forces would have minimal effect. It was determined the cost economically was far higher than the returns. Productivity did fall which was huge in that if this was instituted over a whole country and the result is less productivity, there is absolutely zero way to pay for it. The main take from the initial 4 year study was productively fell less than predicted but it certainly made live easier for the people getting it.
This was likely the biggest study ever done and the most controlled IMO. It did improve people’s health who recieved this money but that was at the expense of the rest of the country paying for it basically all thing being equal, they would get less health care.
Ubi also is payment to everyone. In these examples it is just payment to low or no income people. That is not ubi but simply welfare. Something that is not a bad thing to provide if there is excessive resources to do so.