In traditional societies, the correlation between the two dimensions was often negative (because people with large fortunes did not work and were therefore at the bottom of the labor income hierarchy). In modern societies, the correlation is generally positive but never perfect (the coefficient of correlation is always less than one). For example, many people belong to the upper class in terms of labor income but to the lower class in terms of wealth, and vice versa. Social inequality is multidimensional, just like political conflict.
