Hello Frank,
That would be "hohle Phrase" in German (a statement without content behind it). Not so. They asked themselves the almost same question that I had asked you: Is there a quantifiable means of predicting? Ok, you admitted you aren't an expert on mainstream lead-free solder and neither am I. Fact is, during this whole thread as well as on the web the is an eerie absence of such data. Everybody just seems to hope that it won't be that bad. Now that is a wonderful base for legislative action as we have just seen it with RoHS.
It's not that hasty legislation only happens in Europe although it does seem to fester there. In California some politicians went ahead and mandated an oxygenator in our gasoline to reduce smog. Noble cause, just as reducing lead is. Our gasoline became less efficient, making my car burn about 10% more per mile than with Nevada gas. But the nightmare came only years later. It was found that the chosen oxygenator MTBE had leached into the ground water and was now contaminating one well after the other.
You are preaching to the choir here. That's exactly the point: Maybe there aren't any figures.
But then it may be too late for some industries, mainly in Europe.
Let's hope so.