A weak local association may be substantively important for nonlocal categories. Illustrate with the L ? L model for Table 9.9, showing how the estimated odd ratio for the four corner cells compares to the estimated local odds ratio.

Table 9.9:

Cross-Classification of Mental Health Status and Socioeconomic Status Mental Health Status Mild Symptom Formation Parents' Socioeconomic Moderate Symptom Formation Status Well Impaired A (high) 58 64 94 46 57 94 54 40 57 105 65 60 D 72 141 77 94 36 97 54 78 F (low) 21 71 54 71