No, if the expense were that predictable, the best case would be dispense with insurance entirely, since it effects the cost not at all and imposes overhead, especially insurance where the rates are accurately computed over short periods.
Without uncertainty, there is no point in insurance.
You assumed my views without asking.
My comment only referred to there still being a benefit in choosing to have insurance even with perfect information about risk and expected benefits. At no point did I even imply that I thought "it's irresponsible to own anything".
1. If you choose not to take out an insurance policy, and instead save the money yourself, you will not have the lump sum immediately available to cover catastrophe. Whereas as soon as you start paying insurance premiums you are covered.
2. The payout you receive when you make an insurance claim does not just come from the premiums you have personally paid. In fact, for a rare event, the size of the payout likely exceed the total cost of all premiums you could pay over your entire lifetime. This is because the risk is pooled over all customers, and not all customers will make claims.
Neither of the above 2 points become any less relevant as the insurance premiums become more and more accurately priced.
If insurance can accurately predict losses that will occur and price accordingly, you are paying exactly the same amount plus overhead, on a similar schedule for insurance as directly paying for losses yourself without insurance.
The cost spreading effect (both over time and over individuals) is a direct consequence of the inability to accurately predict losses and the resulting inability to price accurately.
The hypothetical that I'm working with is that the insurer can perfectly price insurance by perfectly estimating the _risk_ or _expected loss_ for each individual customer. They can then pool this risk, take a profit, and everyone wins.
This is what I assumed you meant by "perfectly priced insurance". But I've realized you're talking about the case where insurer has perfect knowledge of the future losses each individual will take. I agree in this case insurance will not make sense. Insurance would be free for most individuals and impossibly expensive for those doomed to catastrophe. (The latter group would be screwed, even if they shared perfect knowledge of the future with the insurer.)
What I'd expect is that you pay into the pool and then after 20 years you've more than paid for the new roof and so you get a new roof.
It should be slightly stochastic financing of your new roof and since a roof has a finite lifetime there should be a new roof at the end of it. It shouldn't be "hey, looks like your roof is about to have issues now, and we only insure new roofs, thanks for the profits, byeeeeee...."
If your roof has a finite lifetime and is approaching the end of its life, the cost of insuring your roof will be close to the cost of a new roof. If your insurance company is not allowed to increase your rate to match your risk (which seems to be the case in California), they will drop you as a customer.
Your previous premium payments insured against the risk of unexpected loss during those earlier policy periods only. They have nothing to do with your current insurance rate.
