Andrew Coyne has written an eloquent piece on the duties of citizenship and how falling voter rates may be leading to a crisis in democratic legitimacy.While I agree with much of what he says, I disagree that compulsory voting is part of the solution. On the contrary, it is likely to make things worse, not better.Let me start with Coyne's argument that, if taxes can be compulsory, so can the vote. I think these are different things and they need to be kept separate.Voting is the most fundamental act of democratic citizenship. Through it, citizens agree to surrender their freedom in exchange for a say over who will govern them.The right to choose our leaders—Consent of the Governed—distinguishes a democracy from authoritarian forms of government, such as monarchies, oligarchies and tyrannies.But democratic consent is never absolute. It is bounded by a mandate and if the government exceeds this mandate, it loses its legitimacy. This is the basis for the idea of the social contract.By contrast, levying taxes is a decision governments only make once they have a mandate; and, in theory, such decisions will usually fall under the mandate.So when it comes to things like taxes, the government is allowed to force compliance because we have already consented to this through the election.By contrast, voting is the primary act of consent—that by which a government's mandate is established and, through it, its legitimacy to act. As such, it should be treated differently. How differently?While I don't think this means compulsory voting is wrong, we should keep it as free and transparent as possible. So if we're going to adopt compulsory voting, there should be a very strong reason. In this case, the costs are unacceptably high and the benefits marginal. Here's why.Voter turnout is one of the most important indicators of the democratic health of our political culture, and hence of the legitimacy of our governments. A government that wins an election with, say, 70% of the vote and a turnout of 80% of the population has a strong mandate. This provides it with the legitimacy to make difficult decisions, even in the face of criticism.By contrast, a government that gets 80% of the vote, but only 40% of the people have turned out, is in a much more precarious position. Moreover, if the turnout has been falling for some time, it likely means people are losing confidence in the system.I believe our falling rates mean exactly this. And I agree with Coyne that this should mobilize the policy community as a whole—and not just political parties—to ask what is going on and how we can re-engage citizens.But I don't see how compulsory voting solves anything. Legitimacy may be amorphous, but it is real and it does matter. It reflects citizens' collective belief that they have chosen someone to govern.But if people are losing confidence in the system, compulsory voting will only mask the malaise by creating the appearance that everything is fine—and that fixes nothing.It's a bit like gerrymandering the unemployment rate to make the impact of a recession look less severe. It doesn't lessen hardship or create jobs. It just relieves the pressure on decision-makers by letting them claim things are better than they are.In short, trading off transparency for artificially higher turnouts at the polls won't strengthen legitimacy. It will only make the real problems less visible.Something like this may be happening in Australia. I've spent considerable time talking to Australians about their political system and while compulsory voting assures a high voter turnout, they still seem vexed by many of the same issues about democratic legitimacy as Canadians—only we have something to point to that shows there's a real problem.In fact, I believe the weak link in the democratic chain lies elsewhere. It is in the mandate, not voter turnout. Over the years, mandates have become increasingly vague. As events move faster and become more interconnected, political campaigns have become less concrete in their plans and commitments. As a result, people are no longer sure where a government's mandate begins or ends.For their part, governments have been pushing the envelope on this, claiming all sorts of things do or don't fall under their mandate. Recall the Harper government's decision to scrap the long-form census. Everyone agreed this came out of the blue, yet the government insisted that it was part of a mandate to protect individual privacy.The most common explanation for why people don't vote—especially youth—is that they don't believe it will make much difference. Governments, they say, will do whatever they want anyway. In other words, they put little stock in the idea of a mandate. But without a mandate the idea of the social contract collapses—and democracy along with it.If we want to address falling voter turnout, I think we should focus more attention on how mandates get defined through the electoral process; and how the tools for holding governments to account between elections can be used to enforce the social contract.If people felt they really knew what a government was elected to do, they might feel more inclined to make a decision about who gets to do it.Dr. Don Lenihan is Chair of the Ontario Open Government Engagement Team and Senior Associate at Canada's Public Policy Forum in Ottawa. He is an internationally recognized expert on democracy and public engagement, accountability and service delivery. Don's latest book, Rescuing Policy: The Case for Public Engagement is an introduction to the field of public engagement, a blueprint for change, and a sustained argument for the need to rethink the public policy process. The views expressed here are those of the columnist alone. Don can be reached at: [email protected] or follow him on Twitter at: @DonLenihan