Fig. 3.

Regulation by informal institutions. Relative frequency of the American spelling for 900 English words as a function of the rescaled time $t*$ ($t*$ = 0 denotes the surpassing year, for all pairs of words considered). Blue dots represent the average over all the pairs of words, and the gray area shows the SD of the data. The solid line is the model outcome, Eq. 2, after parameter fit (${\chi }^2=8\cdot 10^{-4}$, $p=0.97$). (Inset) Distribution $P\left(\tau \right)$ of the years $\tau$ in which the American form overcame the British variant for each word. Vertical lines denote important moments of informal regulations of the US spelling, such as dictionary editions or spelling updates (additional details are in SI Appendix, section 5).