Ichiro Kawachi, MD, PhD

IchiroTrained in both internal medicine and epidemiology, Ichiro Kawachi, has been a pioneer in the field of social epidemiology. Dr. Kawachi’s first foray into public health began as a doctoral student in New Zealand in the 1980’s, when he published a paper quantifying the estimated annual deaths due to second-hand smoke. This paper stoked the ire of the tobacco industry but ultimately led to the passage of historic legislation in New Zealand limiting cigarette smoking and tobacco use. Currently the chair of the Department of Social and Behavioral Sciences at the Harvard School of Public Health, Dr. Kawachi is a professor in social epidemiology and has taught for over 20 years. He has published over 500 articles on social determinants of population health. His books include the Health of Nations with Bruce Kennedy, Social Epidemiology with Lisa Berkman (Oxford University Press, 2000; Completely revised 2nd edition forthcoming in summer of 2014); and Globalization and Health and Social Capital and Health co-edited with S.V. Subramanian and Daniel Kim.

Career in Profile

  • 1985 – Received M.D. from Otago University, New Zealand
  • 1991 – Received Ph.D. from Otago University, New Zealand
  • 1993-NOW – Professor, Harvard School of Public Health, Department of Social and Behavioral Sciences

You have several titles: professor, department chair, social epidemiologist, and more recently, behavioral economist/scientist. Tell me a little about your work in each of these roles and which one is consuming the most of your time these days.

I spend about 75% of my time on research, 20% on teaching, and the remainder on administration. I’ve been very conscientious of trying to protect research time. I have a lab – the Society and Health Lab – that currently has a dozen postdoctoral fellows from all over the world. I try to prioritize research including a NIH-funded R01 project on the aftermath of the tsunami and earthquake in Japan. We’re in the field right now, trying to trace the people who were affected by the tsunami.

I’m still very passionate about teaching. I spend at least twenty percent of my time teaching. My classes are Health and Society, which I’ve been teaching here for over 20 years. I do that twice a year in the summer and the fall. I teach about 400 students altogether each year. Recently, I recorded Health and Society for edX. Thirty-two thousand students registered for it. It was really amazing to see this because as you follow the online chat in the classroom, you can see that the very time if you drop a pin from where one of these comments came from, within a day or so, you quickly draw a map of the world. I also teach Behavioral Economics, which started out small and has done the equivalent of going viral in the classroom because we are in the largest lecture theater now at the Harvard School of Public Health. The chair’s duties are administrative, shepherding academic and strategic concerns of the department. I try to keep it to a tenth of my time.

You were trained in medicine, became an epidemiologist, and have been a leader in the field of social epidemiology. You co-wrote the book on social epidemiology. How did you come to do this work?

I trained as a physician in New Zealand. I switched to epidemiology when I got fed up with doing downstream medicine day after day. It wasn’t what I expected. What I had underestimated was the sheer repetitiveness of day-to-day clinical medicine. I trained in internal medicine. I’d say that 80% of my patients had heart attacks, strokes, congestive heart failure, or chronic respiratory disease. If you take those four diagnoses, they comprise about 80% of internal medicine, at least it was when I was practicing. The bread and butter of medicine are these common things.

What do these things have in common? A lifetime of poor behavior, smoking, stress, bad diet, lack of exercise. So I started to realize that there must be a better way to go upstream and try and prevent these people from ever getting any illness. So, that was my initial stimulus to go from clinical medicine to doing something upstream, such as tobacco control.

I became very active in the New Zealand Public Health Association at that time. I was elected as the National Secretary. Just at that time, the Health Minister of New Zealand was Helen Clark, who later became the longest serving prime minister of New Zealand, and who is currently the head of the United Nations Development Program in New York. Under her leadership, she decided to pass legislation to ban all forms of tobacco advertising in New Zealand and to restrict smoking in workplaces. She was way ahead of the curve. She started thinking about this in 1989 and it finally passed in 1991. This was right at the time when I decided to make the switch to public health. So I became very excited by this.

I spent a lot of time lobbying for the passage of this legislation. That’s how I got interested in public health. Through my interest in tobacco control I then did a PhD in Epidemiology and then came to Harvard, now over 20 years ago. My initial reason for coming here was to study the benefits of stopping smoking in large cohort studies. While I was here, I met Sol Levine, who was one of the founding chairs of my current department. I got exposed to this idea of health inequality. I suddenly realized that the problem of tobacco control is actually one of health inequality. I suddenly realized that unless you tackle inequality, you aren’t going to really tackle tobacco control. People smoke because it is one of the cheapest pleasures, it is one of the few things that someone can have for himself/herself in a life that is full of stress and chaos and few options. That got me interested in social epidemiology.

Twenty years ago, when I was recruited into this department, I wanted to use the term social epidemiology to distinguish what I was doing from what I had been doing before, which was chronic disease epidemiology. At HSPH the students have to declare a major field of study for their thesis. One of the first things I did, when I took on one of my earliest doctoral students [was to suggest] that he declare social epidemiology as his field. Much to my annoyance, this was rejected by the school’s Committee on Admission and Degrees. In 24 hours it had come back and the chair of the Committee had said that there is no such field. That got me sufficiently riled and I decided to work on a textbook. Lisa Berkman also had the same idea and already we got a book contract from Oxford University Press. So we decided to write the textbook together and we declared the arrival of this field. These days, no one questions that there is a field of social epidemiology. Len Syme had been doing similar work for years but I guess he never used the term social epidemiology. The same with Sir Michael Marmot. They were doing it. But they hadn’t declared it an academic discipline. The past twenty years can be seen as an effort to build a training program in social epidemiology, which is what we say that we have at Harvard.

Describe your interests and focus in behavioral economics. What are the implications of this field on public health practitioners and policy? Does it represent a fundamental shift in how we are approaching research and interventions?

I became interested in behavioral economics when, five years ago, I became chair of the Department of Society, Human Development and Health. We are now called the Department of Social and Behavioral Sciences. Being a chair of a behavioral sciences department, I decided to review the curriculum. What are we teaching our students about behavior? Much to my amazement, it turned out that there was nothing in our curriculum about behavioral economics, which has been in the background of economics and psychology for the last thirty years, as it really started in 1980.

I was amazed by this gap because on the one hand you have those behavioral economists and psychologists who don’t speak to public health people, yet all of their examples concern health behavior. They’re practicing public health without a license! On the other hand, when I looked at our curriculum, we are the behavioral science department at the School and there wasn’t a single course listed on our whole department roster that taught behavioral health. So I decided that we better quickly fill this gap.

I think behavioral economics is very interesting because it does seem to me a remarkable confluence of ideas – in disparate fields from psychology to neuroscience to economics and public health – to more fully understand the basis of human behavior. I don’t think that by any means it’s a panacea, but it’s something new that we haven’t done. I think if we do it right, it has the potential at least to reduce inequalities as well. Because we know that all the things we speak about in behavioral economics – the heuristics, the biases, and the problems of delayed gratification – all of these things are even more acute in populations that face poverty and scarcity. To the extent that we can address these things, it has the promise of reducing inequalities and boosting the effectiveness of health behavior interventions.

What is a career success or highlight that you are particularly proud of?

My most efficacious paper to this date remains my 1987 article published in the New Zealand Medical Journal, which I wrote when I was a doctoral student. I always tell this to my students, because much as I try to work toward writing elegant papers in high-profile journals, the one that really had public impact is still the one that I wrote as a doctoral student in epidemiology. Back in 1987, the New Zealand Parliament was starting to debate whether or not they should pass legislation to restrict second-hand smoking. I had this idea to calculate how many deaths second-hand smoking in New Zealand causes. I used the technique of Population Attributable Risk, which I had learned in my epidemiology courses. I got some numbers and did a calculation. I discovered that nearly (an estimated) 300 Kiwis (New Zealand residents) were killed every year by inhaling second-hand smoke in the workplace and the home. Three hundred deaths each year might not seem like large numbers, but in New Zealand, that’s roughly two-thirds of the annual death toll from traffic accidents.

My point was that the New Zealand Traffic Ministry spent millions of dollars in anti-drunk driving campaigns, so why didn’t New Zealand government take passive smoking just as seriously. I published in the New Zealand Medical Journal and it had enormous impact. It was picked up by local anti-smoking organizations that held a demonstration in front of Parliament where 300 of them got dressed in crosses and laid down in front of Parliament. Politicians started to cite it in their speeches to Parliament. The next thing I know, I got a letter attacking the paper. Someone submitted a letter attacking the paper and it was written by none other than Nathan Mantel, who every public health student knows because of the Mantel-Haenszel odds ratio. This world famous statistician turned out to be a consultant for the tobacco industry.

When I saw that letter, I knew that I had made an impact. I had sufficiently disturbed the tobacco companies that they had paid this world famous statistician to attack my paper in the New Zealand Medical Journal (which I doubt he had ever read before my article appeared). To this day, I contend that that was the most important, directly policy-relevant paper I’ve written. It just shows that I peaked early. Students can still do really important work. I’ve never had that kind of success since then.

What is a challenge that you’ve faced or continue to face in your career?

A challenge in behavioral economics and social epidemiology is the massive disparity in power between “us” versus “them”. In this country, at least, economic power has become so concentrated in the last 30–40 years, it’s becoming harder and harder to make an impact through the mechanism of democracy. If you want to make some point of view, it is hard to get it represented through the ordinary channels of media.

It’s exactly like Joseph Stiglitz described in The Price of Equality. He articulated what I always wanted to say about income inequality’s corrosive effects on the body politic. His argument is that the concentration of wealth in the top one percent is distorting political decision-making in a functioning democracy. It is distorting media, the rules of the game by which the economy is run, and I think this is a huge challenge both inside and outside of public health.

To get something done within public health, you have to influence institutions, the laws, and regulation. Developing evidence is the initial step. We also say that lots of policies get made on the basis of no evidence. If there is a will to do it, they’ll do it. If you want something to be passed, at least on our side, you have to have evidence. What researchers at the School of Public Health are doing is providing the knowledge base. As has been said before, that is only one of the ingredients. You have to have the political and popular will to do something and you have to have an appropriate strategy to translate that evidence into policy. Unless those things come together, you won’t get change. The problem with growing polarization is that you can produce lots of evidence but the political will is stuck.

Is there a persistent public health problem that still concerns you today?

I have to say that it is health disparities, persisting inequality between rich and poor countries, and persisting inequality within rich countries. The field of social epidemiology is really an attempt to focus attention on that problem.

It is not enough that the average gets dragged up. You have to lift everybody. There is a lot of attention on global health but basically, you don’t need to go that far. Look in our backyard. You will see disparities in life expectancy that span the entire globe. A man born in a New Orleans’ parish has a life expectancy in his ‘50’s, compared to an Asian-American woman born in a rich Bergen County, NJ, who has a life expectancy of 90. A forty-year difference in life expectancy pretty much spans the average differences in the countries of the globe. I tell young, idealistic youth who want to make a contribution to global health that you don’t have to go all the way to Malawi. You can do something in rural Mississippi. Health centers like the one in Mound Bayou, MS, because basically it’s the model of physician responsibility. The primary care doctors basically said that it’s not enough to provide primary care, you’ve got to invest in educating the people, making them leaders, and make it self-sustaining (Editor’s note: Mound Bayou was the first community health center in the country).

This feature was interviewed, transcribed and partially edited by our guest editor, Ted Henson. The photo was provided by Maki Miyashita.