Fig. 6.

Difference in AIC from complete-case analysis and available data analysis for β₂ and β₃. ΔAIC_Mj,Mk = AIC_Mj − AIC_Mk, is the difference in AICs between two models. Here, k is considered the restricted model and k is nested within j. M1 is Eq. (21), M2 is Eq. (22), M3 is Eq. (23). The leftmost plot describes the test of the linear versus the intercept-only model; the rightmost describes the test of the quadratic versus the linear model. Individual points are coded by color and shape to indicate if a given parameter was statistically significant using a likelihood ratio test.