Saving the Bath Water: An Invited Comment on Krauze and Slomczynski's “Matrix Representation of Structural and Circulation Mobility”

Krauze and Slomczynski propose a mathematical treatment of the mobility table that they claim solves “the crucial methodological problem” in mobility research. We reject their definition of this problem, and we reject their solution. Their proposed solution (1) is not oriented toward describing the process of social mobility or testing theories about the mobility process. Consequently, major issues (for example, the causal effect of socioeconomic origins on destinations, the location of barriers to equal opportunity, and the distances among occupational categories) are ignored in their treatment; (2) has no statistical basis, and hence it should not be used with sample data; (3) yields measures of mobility that are dependent on the marginal distributions, and hence, these measures are not particularly useful for comparative work; and, finally, (4) is arbitrary and unjustified, even if their definition of the crucial methodological problem is accepted. For Krauze and Slomczynski fail to justify one of the critical conditions that is utilized in their solution. A closer inspection of this condition reveals that it is not implied by the definitions set out by Krauze and Slomczynski, as the authors seem to think.