Exactly ! retroactivity is the worst thing to do for a tax. It tells everybody that you can't predict how many tax you'll pay in the future. So your totally sub

Exactly ! retroactivity is the worst thing to do for a tax. It tells everybody that you can't predict how many tax you'll pay in the future. So your totally subject to despoliation. This is the worst message to investors as they can't predict anything about the future if they invest in UE.