Animation 1: Boundedness and Ordinal Resolution Bias
Non-uniform cutpoint spacing and bounded scales together shape the observed mean–inequality relationship
The ordinal resolution effect.
Ordinal probit estimates of life satisfaction typically show probit-spaced cutpoints:
thresholds are denser near the centre of the scale and sparser near the extremes.
This means responses near 5 distinguish finer differences in latent wellbeing than responses
near 0 or 10. Consequence: for the same true latent σ, distributions centred near 5
are better-resolved and produce a higher observed SD than those near the endpoints —
producing an inverted-U in SD, opposite in sign to the pure ceiling/floor effect.
Use all three sliders.
Slider 1: latent mean (μlat).
Slider 2: latent SD (σlat) — controls how strongly the bounded scale truncates the distribution.
Slider 3: cutpoint compression α (0 = uniform, 1 = strong centre compression — middle categories narrow, edge categories wide; the three central gaps are held equal so response 5 isn't artificially squeezed).
The dashed reference curves (recomputed at the current σlat) show the two α extremes; the solid curve is the current blend.
μlat0.00
σlat3.00
α0.00
Obs. mean—
Obs. SD—
Gini—
P80–P20—
α=0 (uniform) — dashed
α=1 (compressed centre) — dashed
α = current slider value — solid
current (μlat, σlat)