Fig. 6.

Effect of including clinic-size quintile as a fixed effect on prediction model accuracy. Plots show the density of values for relative improvement in MAE across 1,000 simulations, with horizontal bars representing the mean value, for different values of γ, which controls the size of the effect of scaled clinic size, f(N _i), on the outcome, Y _ij. All models include clinic-size quintile, N ^*_i, as a categorical fixed effect, because N ^*_i was defined to be observed while N _i was defined to be unobserved. Note that the relative contribution of f(N _i) to the total variance in Y _ij, compared to X _1ij, is equal to γ ². All other parameters are fixed at their base values