Sleep and positive events add little to next day mood forecasts after stressful days

Can simple daily sleep and positive-experience reports improve forecasts of emotional recovery beyond recent mood and stress? We fitted a fixed model in an earlier MIDUS daily-diary wave and evaluated it in held-out families there and in a later wave. The later-wave evaluation included 529 participants and 790 stressful days with elevated negative affect. Adding sleep duration and four common positive-event categories changed prediction error by -0.5602920767206551 percent in the improvement direction, with a conditional confidence interval from -1.4264876842069119 to 0.26668493108151836 percent. Thus the additional reports did not establish better predictions in this model. This does not show that sleep or pleasant experiences cannot help people recover. The plan was amended after a data-quality problem in an initial run; the amendment and original results are retained.