even if it is "threshold" its simply a binary relation and not an explanatory variable at the margin. so, yes...you might be able to weed out some data...but of

even if it is "threshold" its simply a binary relation and not an explanatory variable at the margin. so, yes...you might be able to weed out some data...but of what is left its unliklely to differeniate, except by proxy (as alluded to in the other comments) for something else.