There’s a great new study out this week from our friends at MassPIRG and the Center for Insurance Research that highlights how insurance companies manipulate auto insurance rates so that many good drivers will end up subsidizing bad ones. The report dissects Massachusetts’ new auto insurance rating system, and the title says it all: ‘How You Drive’ Takes a Back Seat to ‘Who You Are.’

The study breaks down the state’s new regulations that prohibit using socio-economic factors – like age, income, credit score, marital status and education – for setting auto insurance rates. Insurers are supposed to place the most importance on how you drive so good drivers pay less. But a loophole lets insurers give ‘discounts’ for things that substitute for credit score or the other prohibited factors instead – like buying home and boat insurance with the same company too. This is a study of Massachusetts’ new rules, but insurers are using the same tactics to overcharge drivers across the country. Here in California, insurers fought the Proposition 103 provision that requires rates be based primarily on driving record for over 17 years.

Bottom line in Massachusetts: If you’re well-off but a crappy driver, you’re still likely to pay less than a young kid scraping to make ends meet. And that goes against every promise made by insurance regulators and the state’s new governor. The Boston Globe lays it out here.