Pfizer Won’t Split and Neither Should Investors

Ummmmmmmm. No.

Five years ago, the world’s largest drug maker said it would study the possibility of a break up. Early Monday, Pfizer (ticker: PFE) finally gave Wall Street its answer. Pfizer would remain a single company rather than splitting into two separate concerns.

The response wasn’t enthusiastic. Pfizer fell 1.8%, twice the...