Mormons use the income from farms to pay for their welfare program; they run for-profit shopping malls, but the majority of their income derives from the required tithing that every "faithful" LDS person must pay. Each year they meet individually or as a family with their local leader and provide an accounting of their tithing.  A refusal to pay can result in the withdrawal of a "temple recommend". Without it, Mormons cannot participate in the highest rites of their church.  The closest comparison for us would be to have to get a "GoodCatholic" ticket punched before we can stand in the communion line.  Come to think of it, Archbishop Chaput would probably be just fine with that.