Thanks Jos. As discussed over email, after seeing your data I now suspect that the reason we arrive at different estimates of the statistical mode (the peak of the distribution graph) is that we use different methods for approximating the shape of the income distribution.
The estimates I provided in my earlier comment are drawn directly from Povcalnet, where the shape of the distribution is based on the best fit between a General Quadratic and Beta lorenz curve. I would favor my $1.22 estimate of the mode since it is faithful to (and therefore consistent with) the Bank's method for compiling global poverty estimates. But no approximation of the shape of the distribution can be definitively correct as all approximations are…approximations.
Thanks again for an interesting post.