I don't know. "effects with no cause" makes me think of the 'quantum soup' at zero-point energy levels: things just appearing and disappearing in some random way. I don't know if that could be classified as 'causeless' though.
More like effects whose cause we can't ascribe... would have a free will component to their cause. It seems a bit silly because wherever you can ascribe a cause, there's no free will, so when is there free will?
