If I remember correctly they tried it on the small sample it didn’t have a meaningful impact and they calculated it would be too expensive to try the whole country, but I could be meant remembering wrong.
http://www.bbc.com/news/world-europe-43866700
Though there was an attempt to walkback or reframe that article:
http://www.kela.fi/web/en/-/contrary-to-reports-the-basic-in...
Sounds slightly different than the parent's phrasing -- the trial was not "walked back", they just decided not to invest more money in it.
Given that the research hasn't been completed, it seems perfectly reasonable for the government to decline to extend the trial; I'd think it sensible to wait until they have analyzed the results before making any decisions (unless they have already seen some early data).
> "The employment effects across the whole experiment will be available by the end of 2019 or at the beginning of 2020."
http://www.kela.fi/web/en/-/contrary-to-reports-the-basic-in...