It seems like you're assuming a zero-sum game here where you are hoping to earn more from insurance claims than you paid in premium. This is not how insurance is supposed to be evaluated, as TFA points out.

You're not against the insurance company. Your decision is relatively separate from theirs.

If I believe insurance is well-priced, the cost ought to be pretty close to the value it’s providing me, maybe cheaper if the insurance industry has some advantage like good rate of return or higher if they are uncompetitive. That makes me indifferent to whether I have insurance in a lot of areas. Therefore, I’m not spending a lot of time purchasing insurance. Nothing against the industry.

Given I’m unable to produce the probabilities necessary to compute the Kelly criterion, I can’t use that to make the decision. Instead, I have to use dumb heuristics like “I need liability insurance to get rid of my risk of ruin” or “I can easily afford to replace my car, but my passion is parking underneath dead trees during storms, so I should pay for comprehensive coverage.”

In either case I have no idea how to compute the probabilities, but I’m still pretty sure I made the right decision.

> If I believe insurance is well-priced, the cost ought to be pretty close to the value it’s providing me

The value of insurance to the buyer depends on the buyer's wealth. The insurance the electronics store offers on the tablet I buy is well-priced for their target audience but not for someone with my emergency expense buffer.

But how do I evaluate how the magnitude of effect of my income on the value I get from the insurance (relative to the average buyer who sets the market price) if I’m lacking the figures to compute the Kelly criterion? Is it useful to me at all as a consumer? Is there version of the formula I can use if I want to implicitly accept the work of the insurance company’s actuaries, but skew the result to account for how I differ from the average customer?

That's an interesting question! The actual risk assessments thr insurer does are obviously confidential, but you're asking whether we can reverse engineer their premiums into underlying probability estimations? So we'd still be estimating probabilities, but based on information leaked from insurers instead of first principles.

Could work! I don't know how, though.