In Appreciation of Adam: Reflections from Friends and Colleagues

ABSTRACT Some of Adam Wagstsaff’s colleagues and research collaborators submitted short reflections about the different ways Adam made a difference through his amazing research output to health equity and health systems as well as a leader and mentor. The Guest Editors of this Special Issue selected a set of six essays related to dimensions of Adam’s contributions. The first contribution highlights his role early on in his career, prior to joining the World Bank, in defining and expanding an important field of research on equity in health (“Adam and Equity,” by Eddy van Doorslaer and Owen O’Donnell). The second contribution focuses on Adam’s early work on equity and health within the World Bank and his leadership on important initiatives that have had impact far beyond the World Bank (“Adam and Health Equity at the World Bank,” by Davidson Gwatkin and Abdo Yazbeck). The next contribution focuses on Adam’s deep dive into providing support, through research, for country-specific programs and reforms, with a special focus on some countries in East Asia (“Adam and Country Health System Research,” by Magnus Lindelow, Caryn Bredenkamp, Winnie Yip, and Sarah Bales). The next contribution highlights Adam’s many ways of contributing to the International Health Economics Association, from the impressive technical contributions to leadership and organizational reform (“Adam and iHEA,” by Diane McIntyre). The next to last contribution focuses on Adam’s long-term leadership in the research group at the World Bank and the long-lasting influence on integrating the research produced into World Bank operations and creating an environment that rewarded producing evidence for action (“Adam the Research Manager,” by Deon Filmer and Damien de Walque). The last contribution pulls on the thread found in many of the earlier ones, mentorship with honesty, directness, caring, commitment, and equity (“Adam the Mentor,” by Agnes Couffinhal, Caryn Bredenkamp, and Reem Hafez).

The thorny philosophical question of what equity in health and in healthcare was could not be avoided entirely. Scrutiny of health policy statements identified two normative egalitarian objectives against which the equity performance of health systems was to be judged: payment according to ability to pay (not healthcare need), and healthcare delivery according to need (not ability to pay). Comparing equity performance across systems required measurement of the extent to which health payments, healthcare utilization, and health itself, were related to ability to pay. To achieve this, Adam and Eddy, along with Pierella Paci, borrowed a tool from public finance that would become the workhorse of a new empirical approach to equity in health and healthcare: the concentration curve, and the closely related concentration index. [7][8][9] Empirical equity analysis founded on the concentration curve/index sustained a number of European research projects, [10][11][12] and spilled over to similar comparative analyses of health systems in Latin America, 13 Asia, 14,15 and Africa, 16 and has been implemented in hundreds of policy reports and research articles around the world. The approach has made it possible to confront policy claims with evidence on relative performance. Its popularity is partly due to its simplicity: essentially, it captures the covariance between health (healthcare) and some indicator of socioeconomic position. Of course, there is a price of such simplicity. A measure of inequity does not explain where it springs from. Adam, again in collaboration with Eddy van Doorslaer, overcame this limitation by introducing a method that could reveal, for example, how differences in demographics, education, location, and health insurance contribute to income-related health inequality. 17 When Adam moved to the World Bank (WB) and set about assessing equity in the financing of low-and middle-income country health systems, he quickly realized that assessment of the proportionality of payments to ability to pay-progressivity analysis-was insufficient to capture the fundamental equity concerns that out-ofpocket payments for healthcare could devastate a household's finances and potentially plunge it into poverty. He responded, with Eddy, by introducing the catastrophic and impoverishing health payments measures 18 that would become the financial protection component of the WHO/WB monitoring of progress toward Universal Health Coverage (UHC) 19,20 and an indicator of the UHC target of the Sustainable Development Goals.
Adam contributed immensely to the development of equity measurement methods and in order to make this work more accessible to practitioners, he initiated the production of a manual in a freely downloadable form. 21 This book, and the many courses that have used it, have given an enormous boost to the worldwide application of equity analysis using household surveys. Adam's research-on health equity as well as many other subjects-has shaped decades of health economics, leaving a legacy that will influence the field for generations to come. were then new to the field. He filled this role admirably, along with making many more direct contributions that marked his stay at the World Bank. One of the most prominent contributions was his technical leadership of the World Bank Health team that drafted the guidance for engaging in the 1999 Poverty Reduction Strategy approach to debt relief and development engagements. The health team at the World Bank was asked to develop guidelines based on best available knowledge on the links between health and poverty. Adam's prominence and publication record in this field made him one of the rare global experts who could bring research findings to direct policy guidance. It did not hurt that Adam's communication skills as a writer and a teacher were exceptional and allowed the health group to contribute substantially and effectively to this global effort. 1,2 Another important contribution was Adam's participation in the country health and poverty reports program. The reports produced through this program provided, for the first time, basic information about socio-economic differences in health status and service use within developing countries. 24,25 They quickly became a standard reference work that has since been widely used in the preparation of country health assessments and program designs. During the first phase of the program, Adam provided invaluable input in resolving the myriad of technical challenges that arose in applying its innovative approach. Soon thereafter, he assumed project leadership, expanded it to cover financial protection, and saw that its outputs were widely disseminated.

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Then came the Reaching the Poor Program. The program involved a series of case studies and analyses to identify inequalities in distribution of health services and outcomes, including how well different strategies and health reached poor population groups. The purpose was to document the experience of these particular case studies and they types of strategies that work, and why they work, as well as to demonstrate the value of methods to assess inequalities, with the hope inspiring others to apply the methods more widely. As with the country report program, Adam's expertise proved invaluable in selecting the projects to be included; and the opening chapter he contributed was a model of clarity in explaining the methods for a lay audience. 26 There were, of course, many more contributions-far more than can be presented in the limited space available here. These examples of Adam's leadership in conceptualization, analytic rigor, teaching, communication and focus on linking evidence to policy and programs illustrate some of the many ways that he contributed to health equity work at the World Bank, and how important these contributions are to the core mission of poverty reduction and improving people's well-being.
Many know Adam for his methodological contributions on the measurement of health equity and inequality and monitoring of Universal Health Coverage. However, during his time at the World Bank, Adam also got deeply involved in health policy work in many countries, with Vietnam 1-9 and China 10-18 perhaps being the most prominent examples. In doing so, Adam worked together with colleagues from operational units in the Bank while also partnering with local researchers.
In both Vietnam and China, Adam's involvement coincided with the implementation of ambitious health system reforms. Although always a consummate researcher, Adam gladly stepped out of the "ivory tower," rolled up his sleeves, and got stuck into the messy business of designing and implementing complex reforms. In both countries, he traveled extensively, engaging senior officials, quizzing village health workers, working with hospital administrators to compile new data sets, and partnering with local researchers.
Adam added immense value through his country work: he shaped the World Bank's policy engagement and advice and contributed to flagship reports that were delivered to government. However, Adam's work also resulted in a rich body of research aimed at addressing important policy questions, and many of Adam's most cited papers emerged from policy-oriented work in China, Vietnam and elsewhere.
For instance, in China, Adam's paper "Can insurance increase financial risk?: The curious case of health insurance in China," published as early as 2008, provided the first hard evidence that extending insurance coverage alone will not necessarily improve financial risk protection. In the following years, China extended insurance coverage for over 96% of its population, but did not reform its fee-for-service payment system which incentivizes providers to over-treat and overprescribe. Health expenditure continued to grow and the impact of financial risk protection was minimal, as Adam's paper has predicted. Adam would be delighted to learn that China is finally reforming its provider payment system.
In Vietnam, Adam made ground-breaking contributions to the understanding of equity in health spending, including on the extent of catastrophic spending and impoverishing health spending and whether government spending was pro-poor or not. At primary care level it was, but at hospital level it was not. He also contributed, in collaboration with other researchers, to evidence-building on a range of other policy issues, including on informal sector participation in health insurance, assessing the impact of healthcare for the poor, capitation payments, and hospital autonomy. More than a decade later, his 2009 book with Sandy Lieberman on health financing and delivery in Vietnam remains an important reference for scholars.
Adam's rigorous approach to health systems research has been highly appreciated by researchers in China, Vietnam and elsewhere. It became a model for those who had the privilege to work with him, and a source of inspiration for many others, including the numerous younger researchers whom he mentored along the way. He was generous with his knowledge and pushed his research collaborators to apply new techniques outside of their comfort zone, such as quasi-experimental analysis and randomized control trials. His narrative about the country and policy context was always very insightful and framed the quantitative analysis in a way that made it easy to see how to apply those findings to policy. As a manager, Adam was welcoming and open. He was supportive and encouraging-creating an environment where researchers could follow leads and be creative. He didn't micromanage, but when he provided feedback, it was always insightful and improved the work. He led by example and not by virtue of his authority. To all, he was a mentor.

Adam the Research Manager
Adam was publicly spirited and a strong advocate for the World Bank's Research Department and the role of research in the Bank's mission. He always took the opportunity to showcase the work of researchers. True to form, he took several deep dives into bibliometric and other types of data to provide evidence for that. More generally, Adam strongly believed in the power of knowledge and the important role that high-quality analytical work can play in the World Bank's country engagements. In order to maximize the relevance and impact of research, he encouraged close collaboration between researchers and staff in the rest of the institution.
Adam personally jumped at the opportunity to get involved in sectoral or country reports and programs. Indeed, in his first 10 years at the Bank he held joint appointments with the Research Department and regional and sectoral units of the institution-a signal of how dedicated he was to ensuring the integration between research and operations. Among other contributions, this resulted in very high-profile outputs that addressed how to reach the Millennium Development Goals, ground-breaking work bringing research into strategic operational engagements in China and Vietnam. It also resulted in his work in shaping the Sustainable Development Goals to include Universal Health Coverage-a result which he was very proud of. His many collaborators across the World Bank are a testament to just how broad his influence was within the institution.
Adam was a giant in his field but to many of us, Adam was more than an academic, a manager, or a mentor-he was also a friend. He was always open to chat, about work or other things. His family hosted us many times at their home, where the parties were always fun. Even our children, who had been invited and were initially reluctant, ended the day by saying "That was fun!" One time, we had gathered in the basement of Adam's house. His daughter had set up the musical game "Rock Band" and she encouraged our kids to try to play the guitar and sing to the tune of "Eye of the Tiger." A little bit later we were joined by Adam who demonstrated the scope of his musical talent.
Adam leaves behind an amazing legacy-at the academic, professional, and personal levels-with great impact for the less fortunate around the world. To the many students, colleagues, and government officials Adam mentored, worked with, and advised, his legacy extends far beyond his unparalleled contributions to the field of health economics. Many talk about the transformative impact that he had on their thinking and professional development, his commitment to making the field of health economics accessible to all, and his genuine interest in people-most who recognized Adam to be a mentor, also considered him to be a personal friend.

Adam the Mentor
Adam's mentorship was remarkable in many ways. First, he challenged people to push their boundaries and achieve their full potential. Adam was a mentor to generations of young health economists; he recognized talent and many of those whom he mentored went on to have highly successful academic careers. However, talent was not a prerequisite; no matter a person's background or abilities, Adam always seemed willing to find the time to answer one's questions. The advice imparted was consistently constructive-even if delivered with frank, and sometimes brutal, honesty. In particular, his comments prompted researchers to rethink how they approached problems, add rigor to their methods, and use data to tell a compelling story. Indeed, Adam had an absolute gift for using data to tell stories! We know he would have smiled at our honest but fruitless effort to substantiate this piece with count data of the number of people whom he advised over the years. But, in the end, there was too much missing data and too much risk of a downward-biased estimate! A second outstanding contribution was how Adam expanded the geographic reach of health economics to graduate students and researchers from underrepresented countries. The field of health economics is strongly dominated by developed countries; 71 of the top 100 health economists are American. Adam was dedicated to promoting the inclusion of researchers from lowand middle-income countries, and helping them (us) to improve our methods and bring our voice to policy decisions. IHEA's newly established Adam Wagstaff Award for Outstanding Research on the Economics of Healthcare Financing and Delivery in Low-and Middle-Income Countries is a testament that will continue to honor that commitment.
Finally, Adam's mentorship was generous, personal, and lifelong. Despite his many commitments, he always found time to give feedback, grab lunch, or make connections with others. Despite being one of the most brilliant minds in the field, he was always curious to hear the ideas of others. Despite leading, he always gave tremendous (and sometimes disproportionate) credit to others. While many sought Adam out for professional advice, his genuine interest was in people. His humor, curiosity, and love of everything fun life had to offer gave all of his mentees a chance to build a long-lasting relationship that went beyond the boundaries of work.
Those who only knew Adam through his work and academic reputation might not be able to fully grasp how special and rare his mentorship was. To those who were privileged enough to know, we challenge you to pay it forward to the next generation of young health economists.