Begging The Question

If you want a good example of the rhetorical trick of 'begging the question' look no further than most advocates of income splitting. In case you haven't encountered it before, 'begging the question' basically means taking your conclusions and putting them in your premises. Wikipedia defines the simplest version as:

For some proposition p:

p implies p
suppose p
therefore p

Consider the debate over income-splitting. At issue is the question of what the basic unit of taxation should be. For example, you might say that the basic unit is the individual. Therefore individuals in the same situation should pay the same taxes. Or you might say the basic unit is the couple, so that any two couples in the same situation should pay the same taxes. Another possibility would be to use the family. Those are the most likely candidates although in theory you could use many things. For example, you could use the municipality as the basic unit so that any two towns in the same situation should pay the same taxes.

The argument for income-splitting is that all couples should pay the same taxes if they have the same income. That is, the argument is that the couple should be the basic unit for taxation purposes.

Now watch how Andrew Coyne makes the case for income splitting:

Fairness does not just mean sharing the tax burden equitably between rich and poor: what economists call “vertical equity.” There’s another kind of fairness, that also has to be taken into account. If it’s important to treat people in different circumstances differently -- ie the rich pay more tax than the poor -- it’s no less important to treat people in similar circumstances the same: what’s called “horizontal equity.” And, when it comes to couples, the tax law doesn’t.

Compare two couples. In Couple A, both spouses work, each earning $50,000. In Couple B, one spouse earns $100,000, the other stays home. The combined household income for each couple is the same -- $100,000 -- yet Couple B pays thousands of dollars more in tax than Couple A. Why? Because the spouse earning $100,000 pays tax at a higher rate, thanks to the progressive income tax, than either of the spouses earning $50,000. Income-splitting amounts to treating Couple B the same as Couple A. It treats like as like."

You see how this works - start by assuming that you determine fairness by assuming that one couple should be treated the same as another, and then show that one couple should be treated the same as another.

Imagine if we had income splitting. I could then write:

"Compare two individuals. Individual A is single and earns $100,000. Individual B is married to a stay at home spouse and earns $100,000. The total income for each individual is the same but individual A pays thousands more in tax than individual B, thanks to individual B splitting income with their spouse. Ending income-splitting amounts to treating individual A the same as individual B. It treats like as like."

Now, if you support income splitting, at this point you're probably thinking, 'sure, but couples are a better basis than individuals.' Which is my point exactly. That is the argument you should be making. Simply assuming that the couple is the right unit of comparison is not a real argument.

To be fair to Coyne, while he relies on begging the question as the core of his column he does make two actual arguments. The first is this :

"Is income-splitting unfair to singles? A couple earns $100,000. A single person earns $100,000. Income-splitting would benefit one but not the other. Shouldn’t they pay the same of tax? No, of course not. Horizontal equity requires that we treat like as like. But a single person and a couple aren’t in similar circumstances. The couple has $100,000 to spend between them. The single gets to spend it all on himself. He thus has more discretionary income -- the amount left over after basic living expenses -- out of which to pay his taxes. It’s only fair he pays more."

Note how Coyne cheats here by comparing an individual to a couple rather than sticking to a comparison of individual vs. individual - which would be the whole point of basing a system on equal treatment of individuals. But let that slide. Coyne treats this as the most obvious point in the world but it is actually pretty weak. For starters, what about children or other relatives living in the house? Surely the income of the couple has to cover their expenses as well. Shouldn't we split the income among everyone in the house if this is our logic. Secondly, what Coyne is arguing is that the individual with the non-working spouse should be provided with compensation for supporting their dependent spouse which raises a couple of concerns: 1) Who ever thought Conservatives would advocate for billions of dollars of incentives for able-bodied adults to sit at home and not work? 2) Even if we allow that you should get a tax break for having a spouse who chooses not to work, the tax code already contains allowance for taking care of dependents. No other types of dependents (children, disabled relatives, etc.) generate a tax splitting benefit so why is this one special?

Coyne's second argument is as follows: "(Or suppose you view it, not as the correction of an inequity, but as a benefit for mothers who stay home with their kids. Is that so awful? Are you also opposed to maternity leave?)"

This argument is even weaker. First of all, it doesn't exactly line up with his comment earlier in the column that, "This isn’t about bribing mothers to stay home, nor is it one of those social-engineering Tory tax credits aimed at rewarding one type of behaviour or another. The fundamental case for income-splitting is one of fairness. " Secondly, is Coyne seriously suggesting that if we were trying to allow parents to spend more time with their children income splitting would be the way to do it? Given that people making six figures will reap the large majority of the benefits from income splitting it seems as though we would be better off providing support for those families which can't *already* afford to have one parent stay home with the kids. I do think government should provide more support for parents to spend time with their children, but this is an incredibly inefficient way to do it.

Anyway, next time you see someone trying to pull this rhetorical sleight-of-hand (the word 'fairness' is the dead giveaway), call 'em on it. If people want to make the case that couples should be the basic unit of taxation, they should make the case. But don't let them start by assuming it and making their case from there.

My own opinion is that the current system of treating individuals equally and providing support as appropriate for those who take care of dependents is more logical than basing the tax system on equal treatment for couples. After all, we are all individuals, but only some people are in couples. Of course, providing a special multi-billion dollar tax break for people to take care of dependents who happen to be able-bodied adults doesn't really appeal much to the (single) conservative in me either. We should call income-splitting what it is - a welfare program for non-working spouses.