What other types of insurance did your inner mathematician prevent you from getting? Did you also skip out on health insurance because the premiums are a markup on the expected value of your health care costs?
1. Cannot afford the worst-case-scenario. (Example: replace your car if it were totaled)
2. You expect the return from claims will exceed the cost of premiums/deductibles. This should never happen if insurance companies are savvy and want to be profitable.
Large companies with a vehicle fleet often self-insure those vehicles (AT&T last I heard) because they can afford every vehicle worst-case-scenario (ignoring liability, which is a legal obligation).
Socially/emotionally, insurance is a peace of mind which is important and valuable to some people. Security and all that.
employer provided health insurance:
$50k salary
$5k health insurance
$50k taxable income
$50k salary
$5k in lieu of health insurance
$55k taxable incomeMy family's insurance healthcare isn't tax-free, which would mean saving $2k or $3k or whatever. It's over $10k of insurance a year that I pay less than $2k for.