Although state governments tend to be less than forthcoming on the matter, researchers are beginning to shed light on the extent to which states subsidize private businesses.
Check it out:

The Mackinac Center published research by Jack McHugh analyzing corporate welfare costs in Michigan between 1995 and 2011, a process made challenging, McHugh said, by “frequent changes in programs and goals, a lack of transparency, and an abundance of spin and puffery in the information that is released.”