If common causes need not screen off correlations, then non-factorizability need not indicate a failure of locality

Finally, there are those who question the assumption that factorizability is a locality condition (Fine 1981, 1986, pp. 59-60, 1989b, Cartwright 1989, chaps. 3 and 6, Chang and Cartwright 1993). Accordingly, they deny that non-factorizability implies non-locality. The main thrust of this line of reasoning is that the principle of the common cause is not generally valid. Some, notably Cartwright (1989) and Chang and Cartwright (1993), challenge the assumption that common causes always screen off