Properties and the Born Rule in GRW Theory

How are properties encoded in GRW theory? In this chapter I discuss an influential answer to this question, the so-called Fuzzy Link. Lewis (1997) argued that GRW theory, when interpreted in terms of the Fuzzy Link, implies that arithmetic does not apply to ordinary objects, an argument now known as the ‘counting anomaly’. I take this argument as the starting point for a discussion of the property structure of GRW theory, and collapse interpretations of quantum mechanics in general. The main lesson to be drawn from the counting anomaly is that the property structure of these theories are more complex than that of standard quantum theories (and classical mechanics) because a seemingly plausible principle, the composition principle, fails