My go-to quip for making decisions based on observable variables when the actual causal relationship is between unobservable variables and outcomes is, "Looking

My go-to quip for making decisions based on observable variables when the actual causal relationship is between unobservable variables and outcomes is, "Looking for your watch under the street lamp." --- For those who aren't familiar with the aphorism, it's from a joke that goes: One night, I came upon a man staring at the ground under a street lamp. "Looking for something?" I asked, and the man nodded, "My watch." "You lost it here?" I asked, but the man shook his head. "I lost it further down the street." "Why look here, if the watch is over there?" The light's better under the street lamp."