Final answer:
An insurer must base premium price differences on solid actuarial principles and risk assessment. This aligns with the law of insurance, which dictates that payouts cannot exceed collected premiums.
Step-by-step explanation:
In order to justify premium price differences among insured individuals, an insurer must demonstrate that the pricing is based on actuarial principles and risk assessment. This means that cost differences should not be arbitrary but should correlate directly to the statistical likelihood of a claim, in line with established actuarial standards. Insurers cannot set premiums that are not actuarially fair without the risk of another group - taxpayers or other insurance buyers - having to make up the shortfall.
This can result in adverse selection and could lead to an insurer exiting the market rather than sustaining losses over time. State insurance regulators also have limited abilities to enforce low premium costs, as insurance companies do have the option to withdraw from states that impose such restrictions.