Laurent Lesnard: Setting Cost in Optimal Matching to Uncover Contemporaneous Socio-Temporal Patterns, Sociological Methods Research 2010 38: 389-419.
This article addresses the question of the effects of cost setting on the kind of temporal patterns optimal matching (OM) can uncover when applied to social science data. It is argued that the balance between indel (insertion anddeletion) and substitution costs determines what kind of socio-temporalpattern can be brought to light. Insertion and deletion operations favor identicallycoded states irrespective of their locations whereas substitutions focuson contemporaneous similarities. The lower the ratio of substitution toindel costs, the closer OM is to the Hamming distance where only substitutionsare used. The higher this ratio, the closer OM is to the Levenshtein IIdistance, which amounts to finding the longest common subsequence.When the timing of sequences is crucial, substitutions should be favoredover indels and their costs should be carefully fixed. Ideally, substitutioncosts should vary with time to better take into account the timing of thesequences studied. As indels warp time, hence the timing of sequences, itis suggested to use only substitution operations with time-dependent costsinversely proportional to transition frequencies whenever the timing of sequencesis central. This OM variant, coined dynamic Hamming matching, isapplied to the question of the scheduling of paid work where timing is critical(1985 and 1999 French time use surveys, N ¼ 7,908) along with three classicalOM variants (Hamming and Levenshtein I and II). As expected, the two Hamming dissimilarity measures fare better to identify patterns of workday schedules, as measured by entropy, than the two Levenshtein ones.