AP Photo/Richard Drew, File The logo for ExxonMobil appears above a trading post on the floor of the New York Stock Exchange. L ess than two months ago, hundreds of Baton Rouge educators voted to stage a walkout in protest of requests by ExxonMobil for millions of dollars in local property tax abatements. Working in conjunction with a faith-based group, Together Baton Rouge, the teachers called on the state to direct the proposed corporate subsidies back into public education. ExxonMobil has defended its tax breaks as necessary to create a stable and hospitable business climate. Unlike teachers in Baton Rouge, who learned of the oil giant’s exemption from their state’s longstanding Industrial Tax-Exemption Program , most jurisdictions have lacked any real picture of how much money public schools are losing, or could lose, due to corporate tax abatements. That all began to change in 2015 when the Governmental Accounting Standards Board, a private organization that sets professional...