If there is one thing that most economists agree about in the realm of tax policy, it is that it's best to broaden the base of any tax, all else being equal. That means minimizing the number of deductions and exclusions from taxable income in order to lower marginal rates and reduce distortions.

I don't think it says anywhere in the Bible that tithing should be calculated on a before-tax basis.

If we think that high marginal tax rates are bad because they distort incentives, the same is then true for tax subsidies.

Richard Thaler Quotes