Before revision:  In such an environment, laissez-faire may result in a highly unfair and inefficient outcome -- myopic firms are reluctant to hire minority workers because the lack of data about minority workers prevents accurate estimation of their performance. Consequently, minority groups could be perpetually underestimated -- they are never hired, and therefore, data about them is never accumulated.
After revision:  Laissez-faire causes perpetual underestimation: minority workers are rarely hired, and therefore, data about them is never accumulated.