Scheffer et al have a paper out in PNAS on inequality in nature and human societies. They use fairly simpleminded models to demonstrate that inequality increases with time, unless counterbalanced by crisis or institutions. As scale increases, this effect becomes dominant. They analyze many communities including plants/trees, fish,rodents, insects,nushrooms, bacteria, and plankton and find broadly yhe same picture.
"Starting with a perfectly equal distribution of wealth, inequality quickly rises until a few actors
appropriate most of the wealth (Fig. 3 A and B) and the vast majority ends up with almost zero wealth. Very much the same pattern arises from the ecological model (SI Appendix, section 5). The extreme inequality may seem surprising, as no actor is intrinsically better than the others in these entirely chance-driven worlds. The explanation, mathematically, is that due to the multiplicity (gains and losses are multiplied by the actual wealth), absolute rates of the change tend to nil as wealth goes to zero (19). This causes very low wealth to be a “sticky” state, in the sense that getting out of it is extremely slow."
"There are essentially two classes of mechanisms that can reduce inequality: suppression of dominance (Fig. 2, III) or lifting the majority out of the sticky state close to zero ..."
"Occasional disasters, such as major wars, may have an equalizing effect by destroying capital or inducing redistribution, but in the long run inequality generally returns to the previous level (31)."
"Focusing on Western Europe, we can see how in the Middl Ages, and especially in the 12th to 14th centuries, local communities reduced inequality by limiting opportunities for transacting and accumulating land and capital, and developing mechanisms of redistribution, through guild or community systems, operating at the local level, where most of the exchange and allocation of land and capital took place (4). However, these town and village communities saw their institutional frameworks eroded by the growth of international trade, migration, and interregional labor and capital markets, as well as by the process of state formation with the rise of more centralized bureaucracies in the (early) modern period, triggering a long episode of rising inequality (5, 7, 35). In the late 19th century and early 20th century, institutions aimed at effectively constraining wealth accumulation were developed at the level of the nation state, with the emergence of tax-funded welfare states. Perhaps the most conspicuous of these institutions is the introduction of the inheritance tax, which limits wealth transfer to the next generation (2). Over the past decades, however, globalization has given way to a more unconstrained use and accumulation of wealth (29). The financial playing field for the wealthiest is now global, and mobility of wealth has greatly increased, providing immunity to national tax- ation and other institutional obstacles to wealth accumulation."
doi: 10.1073/pnas.1706412114
Open access. Read all about it.
I attach fig 1.
sidd
Postscript: I notice van Nes is an author. I wonder if he has any empirical dynamics/convergent cross mapping overview on the cycles of inequality ?