What does the rule against perpetuities primarily prevent?

The rule against perpetuities is a legal doctrine primarily aimed at preventing indefinite limitations on the use and transfer of property. Specifically, it ensures that no interest in property can be held for an extended period of time after the death of a relevant party, typically measured by the lives of certain individuals. This rule is designed to promote the free transferability of property and to avoid tying up assets indefinitely in a manner that can restrict their utility and ownership.

By ensuring that property interests must vest, if at all, within a specific timeframe — usually within 21 years after the death of a measuring life — it encourages owners to make decisions about their property without imposing limitations that could potentially extend far beyond their lifetimes. This maintains efficiency in property markets and helps to avoid complex legal hurdles that could arise from perpetual ownership restrictions.

In contrast, the other choices do not accurately reflect the primary purpose of the rule against perpetuities. Long-term leases and concerns about urban overpopulation or excessive land taxes are related to different legal and economic frameworks and are not pertinent to the objectives of this rule.