Land rights are unstable and not legitimate unless there is a mechanism to reduce inequality

Property rights are utilitarian in the sense that without them the community would suffer. It is beneficial for people to be able to retain the output of the labour. Even though we do not make land it is still beneficial to allocate land rights so that land can be farmed and occupied without fear of being removed. This allows people to invest in the locality, whether in the construction of buildings or the preparation of food crops.

The utility of land rights is threatened when land ownership becomes too unequal. The value in allocating land to each individual can be measured by the marginal advantage of yet more land. If someone has not much land, then a little extra would be very welcome, but someone with an excess of land (as defined by the Lockean proviso) would derive no great advantage from having more. Each unit of land is more important to the one with a small quantity. If land ceases to be above a certain level of personal importance to the owner, (per unit of incremental increase) measured objectively, not idiosyncratically, relative to the remainder of the population then this land is not legitimately owned.

We do not own the (entirety of the) land if extra land is of little personal value, measured objectively, not subjectively. We have no right to own significantly more land than our neighbours, for whatever reason, if they can be said to not have sufficient land of their own.