I don't think this fits the definition of basic income.
> Whatever income participants earned was deducted from their basic income at 50 per cent
That is equivalent to a massive 50% tax rate on every dollar earned. It seems to me the whole point of UBI is that its universal and not conditional on how much you earn otherwise.
Yup, this combined with the difference in income for couples vs. individuals mentioned by another commented smells to me like the program had a lot of means testing built in. I wouldn't be surprised if this skewed the results of the experiment in ways that reflect badly on it.
But the funding mechanism isn't at issue here. The point is that for every dollar earned the participants lost 50 cents due to a decrease in support from the basic income. That's a massive disincentive to work.
Any practical UBI will require a large increase in taxes. If this isn't an income tax, it will be a payroll or sales tax, which both have a similar effect. A UBI pilot needs to model that tax just as much as the actual money transfer. If a practical UBI system contains a "massive disincentive to work", a model of such a system should contain this as well.
You make a good point, a good UBI pilot would incorporate the necessary tax increases.
But that's not what this study did. Crucially, the disincentive to create only applies to low income earners. Under, UBI everyone pays the taxes and thus everyone gets that disincentive to work. If we want to see what UBI would do, we should actually do UBI.
> Whatever income participants earned was deducted from their basic income at 50 per cent
That is equivalent to a massive 50% tax rate on every dollar earned. It seems to me the whole point of UBI is that its universal and not conditional on how much you earn otherwise.