Professor David Duff teaches tax law and tax policy at the Peter A. Allard School of Law. In 2014, he was awarded the Alumni Award for Research at the 2014 Allard Alumni Association Achievement Awards. Professor Duff joined the law school in July 2009 after visiting at the Faculty during the 2008-09 academic year. From 1996 to 2008, Professor Duff taught tax law and policy at the University of Toronto Faculty of Law. Prior to this, he was a tax associate at the Toronto office of Stikeman, Elliott. He was also employed as a researcher with the Ontario Fair Tax Commission from 1991 to 1993 and as a tax policy analyst with the Ontario Ministry of Finance from 1993 to 1994.
Professor Duff has an LL.M. from Harvard and an LL.B. from the University of Toronto, master’s degrees in political theory from the University of Toronto and economics from York University, and a B.A. (Honours) from Queen’s University. He has been a visiting scholar at the law faculties at Auckland University, McGill University, Oxford University, and the University of Sydney, and is a Research Fellow of the Monash University Taxation Law and Policy Research Institute, an International Research Fellow of the Oxford University Centre for Business Taxation, a member of the Tax Academy of the Americas, and a member of the Board of the Canadian Tax Foundation.
What do you think are the most interesting topics in tax at the moment?
Well, tax is so fascinating, I could never just choose one. So, I think there are three that I find very exciting at the moment.
The first - and this is one of my research areas - is environmental taxation and how we can design a viable model for a carbon tax. I started working on that when I started caring about climate change, about a decade ago. I think it's terribly important.
The second is international tax. Cross-border trade and investment has expanded enormously over the past 25 years, and international taxation is having to change in order to keep pace, so it's a fascinating area. It's fantastic, and complex, and I love to teach it.
And finally, there's the ongoing issue of income and wealth distribution, which is a subject of greater attention after the global financial crisis. This was the main consideration that motivated me to get interested in tax law in the first place.
What's the direction of your research on environmental taxation?
Clearly, climate change is a reality, and increased carbon dioxide in the atmosphere is the cause. In order to limit carbon emissions, we need to place an effective price on carbon, but measures thus far have been inadequate. International agreements like Kyoto haven't worked because it's impossible to get every country on board
Some jurisdictions have introduced carbon taxes or emission trading schemes, but they're generally quite limited, so as not to disadvantage domestic producers. So the challenge is to design a carbon tax that does not damage domestic competitiveness and does not require international agreement.
I think that a good model on which to base such a carbon tax is that of a value added tax (VAT) like the GST, which would apply to imports but not apply to exports, thereby shielding domestic producers from any competitive disadvantage. France introduced the first general VAT in 1954 and this tax has spread around the world without the need for any international agreement, simply because most countries consider it to be in their best interests. If a carbon tax were to be based on the same approach, it might succeed where other measures have failed. Indeed, since revenues could be used to reduce other less efficient taxes, there could be a first mover advantage for a country adopting such a tax.
While there are challenges to making such a tax administratively feasible and compatible with international trade law, I think that these can be addressed, and that Canada is well-placed for various reasons to introduce such a tax.
And you mentioned that you love teaching and writing about international taxation?
I do. As I said, because cross-border trade and investment has increased so much over the past 25 years, international tax rules are struggling to keep up., which means that the law is this area is changing rapidly.
A particular interest of mine in this area is international tax avoidance and evasion, which countries are attempting to address through changes to domestic tax rules and tax treaties, as well as increased exchange of information. The G20 has made this issue an area of particular concern in recent years, and the Organization for Economic Cooperation and Development has a current project to encourage changes to prevent "base erosion and profit shifting" (BEPS) by multinational enterprises. So this is an area where concerns about tax fairness and efficiency come alive in current developments in the law.
It sounds like fairness is really important to you?
Why does someone go into tax law and want to teach it? To make the system fairer. And to make it more efficient. A lot of people like to say "Fairness is in the eye of the beholder." I think there's more to it than that. I think we can have criteria about what makes things more fair and less fair, and tax law is a great example of how to do that.
Inheritance tax is a good example. In our society, we generally value the idea of merit and equal opportunity, yet we permit large fortunes to pass from one generation to the next without a tax on the transfer. Although Canada abolished its estate tax in 1972, other countries like the United Kingdom and the United States continue to levy these kinds of taxes, and I think that they have an important role to play in a fair tax system.
You hold the all-time record for the most downloads on SSRN of all Allard School of Law faculty ever. What does that mean?
The Social Science Research Network (SSRN) is an online database of academic articles and abstracts, to which many academics around the world subscribe, which distributes updates on newly published articles and working papers directly to subscribers through their computers. As a result, it's a fantastic way to make one's research available to other academics - who are much less likely to track down a hard copy of an article than to access an electronic version.
Unfortunately, we live in a world where achievements are too often measured by simply counting things like downloads, so I wouldn't want to make too much of this. More importantly, I think it's a great way to reach a wide audience of potential readers who might otherwise remain unaware of one's work, so I'm pleased that people seem to be reading (or at least downloading!) my articles. It's particularly pleasing to be at a conference somewhere and to have someone from another country tell you that they've read one of your articles - which likely would not have happened but for electronic dissemination of research through the SSRN.
You're known for being passionate and enthusiastic about tax. How do you keep up your enthusiasm year after year?
It's easy because tax law changes regularly, so it's alive and always new. Like law generally, the cases always present interesting stories, so I like to have fun with that. And it's all such an exciting intellectual exercise.
Teaching the basic tax course is so much fun. People come into my course thinking that they're going to hate tax, or that tax law is boring, but I try to show them that it really matters. In my first class, I ask my students, "Who's ever sued anyone or had criminal charges brought against them?" and I might get one or two people raising their hands. And then I ask "Who's ever filed a tax return?" and almost all of them have. This is an area of law that touches people more deeply and more widely than any other field t of law. Every year, we have this intimate relationship with the law by filing our tax return, and these laws really affect people's lives.
I knew very early on that I wanted to teach tax. It's easy to stay enthusiastic because I really think it matters. I love it.
In addition to Professor Duff, the other winners of the 2014 Allard Alumni Association Achievement Awards were: Michael O'Keefe, QC, Anne Stewart, QC and Thomas Berger, OC, OBC, QC. Click here to see photographs of the event.