On problem areas in grammaticalization

In a number of recent studies on grammaticalization, it has been argued that the Lehmannian parameter of scope decrease does not work, and that instead scope increase is involved. In this paper I will look at a classic case of grammaticalization, that of the English modals, and suggest that the scope increase observed here can be seen as a case of scope stability provided one takes other constructions involving modals into account. Generally, it will be argued that grammaticalization should not be seen as an independent unidirectional mechanism driving change. Rather, each case of change is the result of the synchronic variable system in which it functions, in which analogy and frequency, as well as economy provide the main mechanisms for change.