There have been multiple tests of the ideas behind BI:

* https://en.wikipedia.org/wiki/Mincome

* https://decorrespondent.nl/541/Why-we-should-give-free-money...

* http://freakonomics.com/podcast/fighting-poverty-with-actual...

The problem is that it often isn't possible to falsify or confirm ideas based on limited tests. You can set up a minimum income for one town, or give money with no strings attached to several groups of people, but it won't answer a lot of the long term societal questions. It's like asking if you can test social security or universal healthcare. Those tests might not illuminate problems that could occur on a large scale, 50 years down the line.

Sometimes the only way to test something is to do it.