Perhaps someone can help me with this. Mercury is viewed as having achieved some sort of coup by gaining DOI acquiescence regarding the use of credit. Having said this, I believe Mercury is prohibited from using credit in its largest state -- California. If this is the case, where did they acquire the skill to use it in a contentious market like New Jersey (with large stakes) and where does the confidence come?
Mercury uses credit in the other states, so Mercury has about $250,000,000 in premium volume that has credit as a component of the rating. In addition to that, credit is not rocket science. There are a number of studies available for review to get a comfort level with the use of credit data in insurance.