W. Scholl, Richard, Differentiating Organizational Commitment from Expectancy as a Motivating Force, Academy of Management review , 6(4), 1981, pp. 589-599
If the concept of organizational commitment is to have any analytical utility, it must be differentiated from the concept of expectancy. Viewing commitment and expectancy as two independent behavioral forces makes it possible to explain instances of commitment not explicable according to exchange or expectancy theories, such as remaining with an organization despite reward valences being reduced, inequity developing, and expectations not being met. Commitment defined as a force that maintains behavioral direction when expectancy/equity conditions are not met has at least four sources: investments, reciprocity, lack of alternatives, and identification.