I have looked into US insurance, and teh cost difference seems to come down to as follows:
Liability:
MUCH lower in the USA. As a result, the insurance company pays out less. So they charge less. Of course, you wreck something beyond your $25,000 coverage (as in, a bike with a small visit to a hospital for a broken leg) and you are on the hook for much much much more money. In the USA, once your insurance is used up, they walk away. The victim now sues you for pain and suffering, and you are out millions. In Ontario, the victim cannot sue for such things, but as a result of this, the insurance company must keep paying out until the victim is back to their original status. It takes longer to use up $2M in Canada, than $25K in the USA.
Accident Benefits
No such thing in most states. If you are injured in a crash, and dont have this coverage, the bills are up to you. Being a private healthcare system, you won't be able to afford any of your recovery at all. Up here, the insurance companies pay a large amount out. On my policy, this is almost 60%.
If you were to tailor a US plan to be identical in every way to an Ontario plan, it actually adds up nearly the same. In most cases after that, they can be a little lower because they have 1-x the population to draw from.
Peggassus: Texas bike accident stats are LOWER because they never have to re-learn riding after months off of winter. That is why southern states are cheaper.
VifferFun: here is one for you: I have read that statistically, bike accident rates increase aove age 55, to a point that they are higher risk than a 16 year old newbie. If this is the case, then why do their rates continue to drop?
As well, a 16yo on a supersport, knowing the raping the insurance co will give them with a claim, will not usually make a claim, especially if they are not formally charged. A mature adult is more likely to actually claim damage from a small accident, charge or not. That being true, shouldnt the stats show that younger riders appear safer?