Sam Brunson, a Loyola (Chicago) professor specializing in tax law, searched IRS private letter rulings and sums up the results at the Mormon website By Common Consent (via Paul Caron/TaxProf, who assembles other links). For some academics’ views on whether the Bob Jones U. precedent (exemption denied to educational institution on grounds of race discrimination) will or should be pushed further into other areas, see Inside Higher Education and Caroline Corbin, SSRN (sex discrimination).
More on the Bob Jones U. case: Regulation magazine, Jan./Feb. 1982, more via Steven Hayward. More on the parsonage (housing) allowance, one bit of the tax code that does favor religious entities over otherwise comparable nonprofits: Ronald Hiner and Darlene Pulliam Smith/Journal of Accountancy, Erwin Chemerinsky/Duke (anti), Jonathan Whitehead and Becket Fund (pro). Journalists stirring the pot recently: Felix Salmon, Fusion; Mark Oppenheimer, Time.