Dead business units tell no tales, and much quantitative research on MNEs shows some degree of "survivor bias" in addressing only those firms that have enjoyed enough success to sustain their international operations. Some research designs can clear themselves of any charges of distortion from survivor bias, but others cannot. Consider some business strategy that we observe to yield more than normal profits for the firms employing it. Can we safely advise potential adopter that the strategy is a sure bet? Not without checking whether another set of firms adopted the same strategy unsuccessfully, ran fatal losses, and hence disappeared off the screen.
Indeed, a standard economic model holds that risk-neutral firms, with equal access to some risky market and well informed about the distribution of its profits and overall average expected return in equilibrium "normal profits.