The cited studies, like most sociopolitical studies, probably don't prove anything. The article doesn't specify how the subjects were selected, unless I missed something. If I were an advocate for UBI and wanted to organize a study like this, I'd make sure to select people who are likely to keep working and not just quit and smoke weed all day so I could reinforce my narrative. If I were an opponent of UBI I'd do the opposite and enroll people who are unlikely to keep working when they don't have to.
"To determine whether the measured effects were actually due to receiving the basic income and not, for example, to broader societal developments, the Basic Income Pilot Project was designed as a randomised controlled trial. This ensured that the participants in the control group were so-called 'statistical twins' of the basic income group. This meant that they were very similar in their sociodemographic characteristics and differed mainly in whether or not they had received a basic income.
Both groups were essential to the success of the study. Only by comparing their experiences could scientific conclusions be drawn.
To prevent bias, care was also taken to ensure that both groups included equal numbers of ideological supporters and opponents of basic income.
The study focused on people between the ages of 21 and 40 living alone in a household with a net income of between €1,100 and €2,600 per month. We explain why these characteristics were chosen in our journal."
Arguably, those people won't be productive members of the society either way. With UBI, they could even be less likely to shoplift, mug/rob people, or otherwise cause harm.
