However, the emerging new breed of financial economists quickly saw the elegance of the Black-Scholes-Merton solution. The expected return on the underlying stock and investors' levels of risk aversion did not appear in the Black-Scholes equation: their arbitrage-based arguments did not require knowledge of those. Herbert Simon's jibe that finance was a field dependent on unobservable variables seemed to have been answered decisively, at least as far as expected returns and risk aversion were concerned.

Donald MacKenzie, An Engine, Not a Camera, loc. 610