What is the main advantage of a joint life annuity?

A joint life annuity is designed to provide a steady stream of income for two individuals for as long as either of them is alive. This structure ensures that the payments continue until the death of the last surviving party, which is why the guaranteed payout for both parties' lifetimes is the primary advantage. This feature is particularly beneficial for couples or individuals who want to ensure financial security over the lifetimes of both parties.

The setup alleviates the concern that one person could outlive their financial resources, as it guarantees that the annuity payments persist regardless of which individual passes away first. This can be an essential aspect for planning retirement finances, especially for spouses or partners who rely on each other’s income.

In contrast, the other choices do not encapsulate the main benefit of a joint life annuity. Increased payments upon the first party's death may occur in different types of structuring, but it isn't a standard feature of joint life annuities. Flexibility in changing beneficiaries typically applies to life insurance policies rather than annuities, and while some annuities might have higher returns, the fundamental strength of a joint life annuity lies in its longevity and reliability in payouts for both individuals.