In Donald MacKenzie's study on the financial turn of economics, he highlights
the role of the self-fulfilling prophecy (positive feedback) of mathematical models
upon reality, through the example of the Black-Scholes-Merton model. At first
the correspondence between the model and actual prices was fairly inaccurate
(the model did not refiect reality), yet as traders began to rely on the modeltaking
up its mathematical claims of legitimacy, directly using its projections in their
practice through the dissemination of purchased pricing charts-the model began
to create reality, it became a tool of the trade-what MacKenzie calls 'an engine,
not a camera', a (once inaccurate) model (now) driving reality. [...]