About last night… GOP presidential candidates used last night's debates as an opportunity to tout the highlights of their tax plans. Kentucky Senator Rand Paul questioned Florida Senator Marco Rubio's conservative credentials  for Rubio's plan to expand the child tax credit. Jeb Bush promised to make tax reform his top priority and Ben Carson said his flat tax will have a low-income exemption but tax mortgage interest and charitable gifts. Others stuck to broad strokes about their own plans. Senate GOP leaders will use reconciliation to try to repeal key pieces of the Affordable Care Act. Doing so would block the Democrats’ opportunity to filibuster. The House-passed bill retained several ACA tax increases, health insurance tax subsidies, and Medicaid expansion, but repeals the Cadillac tax. The Hill reports that  Senate Republican leaders want to go further than the House effort. But can they get the votes? And would it matter? The President’s veto pen is locked and loaded. Should governments use a new kind of “sin tax” to help you live a safer, healthier life? TPC’s Donald Marron takes a look. Policymakers often use sin taxes to mitigate the costs on society, what economists call externalities. For example, since smoking increases national healthcare costs, policymakers levy a cigarette tax. But what about the danger posed to the smoker herself, known as an internality? Does a cigarette tax make her smoke less? It depends. In his new paper, Donald finds a weak economic case for sin taxes that only improve an individual’s well-being. Eleven companies will face questions from EU lawmakers next week. The European Parliament’s special tax committee wants to ask Amazon, McDonalds, Barclays, and eight other multinational companies about their low-tax deals with certain member nations. The meeting takes place on November 16. It’s a second attempt. The first hearing fell apart when most corporate invitees declined to attend. Interested in subscribing to the Daily Deduction, the Urban-Brookings Tax Policy Center summary of the day’s tax news? Sign-up here to get the Daily Deduction delivered to your inbox every morning. If you’d like to tell us about a new research paper or have any comments about our feature, write us at dailydeduction “at” taxpolicycenter “dot” org.