Nevertheless, the availability of convenient material implementations of the Black-Scholes-Merton model (notably Black's "sheets"), and their use to identify arbitrage opportunities particularly opportunities for "spreading" most likely had the effect of reducing discrepancies between empirical prices and the model, especially in the econometrically crucial matter of the flat-line relationship between implied volatility and strike price. As was noted in chapter 6, there was thus a homology between the way the model was tested econometrically and options market practices based on the model. Use of the model does indeed seem to have helped to create patterns of prices consistent with the model.

Donald MacKenzie, An Engine, Not a Camera, loc. 1154