Bias in cross-sectional analyses of longitudinal mediation.

Most empirical tests of mediation utilize cross-sectional data despite the fact that mediation consists of causal processes that unfold over time. The authors considered the possibility that longitudinal mediation might occur under either of two different models of change: (a) an autoregressive model or (b) a random effects model. For both models, the authors demonstrated that cross-sectional approaches to mediation typically generate substantially biased estimates of longitudinal parameters even under the ideal conditions when mediation is complete. In longitudinal models where variable M completely mediates the effect of X on Y, cross-sectional estimates of the direct effect of X on Y, the indirect effect of…

• NI
  National Institute of Mental Health

  Award: R01MH64650
• EK
  Eunice Kennedy Shriver National Institute of Child Health and Human Development

  Award: P30HD15052