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Ellen P. Green

health and behavioral economist

Contact Information:

Assistant Professor at School for the Science of Healthcare Delivery,
Arizona State University

Research Affiliate at the Mayo Clinic

Ellen.Green [at] asu [dot] edu

Office Phone:
(602) 496-2879

(602) 496-0544

Short CV:

Academic Positions:
Assistant Professor
College of Health Solutions
Arizona State University

Research Affiliate
The Mayo Clinic, AZ

Virginia Polytechnic Institute and State University, Ph.D. December 2011
Dissertation: A Study of Human Decision-Making in Economic Games

Research Interests:
Health Economics, Behavioral Economics, Experimental Economics

“Experimental and Behavioral Economics of Healthcare.” joint with Cox, James C. and Heike Hennig-Schmidt Journal of Economic Behavior and Organization [2016]

“Angels and Demons: How Individual Characteristics, Behavioral Types and Choices Influence Behavior in a Real-Effort Moral Dilemma Experiment” joint with Bejarano, Hernán, and Stephen Rassenti Frontiers in Psychology [2016]

“Payment Systems in the Healthcare Industry: An Experimental Study of Physician Incentives.” Journal of Economic Behavior and Organization [2014]

"Compensation and Production in Family Medicine by Practice Ownership." joint with Essary, Alison C., and David N. Gans Health Services Research and Managerial Epidemiology [2016]

“Lessons Learned from Implementing the Patient-Centered Medical Home.” joint with John Wendland, Colette Carver, Hughes Cortney, and Sun Ki Mun, International Journal of Telemedicine and Applications [2012] [First Author]

Working Papers:
“Payment Scheme Self-Selection in the Credence Goods Market: An Experimental Study” joint with Bejarano, Hernán, and Stephen Rassenti

“The Ethics of Living Organ Donation: A Systematic Literature Review” joint with Azra Ariff, Bruce Kaplan, and Gabrielle Knight

Works In Progress:
“Gender Effects and Selection in the Credence Goods Labor Market” joint with Anjali Agrawal, and Lisa Lavergne

“Using Behavioral Economics to Transform Health Care Policy: An Experimental Study of Payment Scheme Sorting” ISSR Seed Grant ($6,000) PI

“Using Behavioral Economics to Transform US Health Care Delivery and Disease Management” Mayo-ASU Seed Grant ($50,000) Co-PI with David Etzioni, M.D.


I am a health economist with interests in behavioral economics and experimental design. The goal of my research is to contribute to the understanding of how incentive schemes and other variables impact the efficacy and efficiency of the healthcare industry.

My research focuses on the role of payment structures and other non-monetary motivators in healthcare delivery, a relevant yet poorly understood aspect of the US healthcare system. Through a series of laboratory experiments, I evaluate the quantity and quality of healthcare services induced by physician incentive structures. This research has pertinent policy implications among both developed and developing economies and contributes to several literatures including healthcare incentive structures, real-effort experimental design, and intrinsic motivations in contract design.

My paper, “Payment Systems in the Healthcare Industry: An Experimental Study of Physician Incentives,” explores alternative physician payment mechanisms. This paper demonstrates that the most commonly employed payment mechanisms in the healthcare industry provide poor incentive structures, resulting in undesirable contractual outcomes. For instance, under retrospective payment systems, the experiments suggest that healthcare is overprovided and mistake prone. This paper was honored with the 2011 Lee B. Lusted award in behavioral economics from the Society of Medical Decision Making. Only one paper receives this honor each year in recognition of outstanding and innovative healthcare research. In response to that research, I was invited to present my work at one of the Economic Science Association’s sessions at the 2013 ASSA meetings in San Diego. The results of this research have caught the attention of many researchers at academic conferences and in the healthcare industry.

Past Research:

“Payment Systems in the Healthcare Industry: An Experimental Study of Physician Incentives.” The Journal of Economic Behavior and Organization

Policy makers and the healthcare industry have proposed changes to physician payment structures as a way to improve the quality of health care and reduce costs. Several of these proposals require healthcare providers to employ a value-based purchasing program (also known as pay-for-performance [P4P]). However, the way in which existing payment structures impact physician behavior is unclear and therefore, predicting how well P4P will perform is difficult. To understand the impact physician payment structures have on physician behavior, I approximate the physician-patient relationship in a real-effort laboratory experiment. I study several prominent physician payment structures including fee-for-service, capitation, salary, and P4P. I find that physicians are intrinsically motivated to provide high-quality care and that relying exclusively on extrinsic incentives to motivate physicians is detrimental to the quality of care and costly for the healthcare industry.

“Should I stay or Should I Go? An Experimental Study of Decision Support Devices and Hospital Discharge,” [First Author]

joint with Sheryl Ball and Landis Atkinson.

Efforts to reduce frank medical errors and promote evidence-based clinical practice in the U.S. health system have reduced clinical judgment in discretionary decisions. With a specific application to hospital discharge, our experiment expands on l k, Fehr, and Fischbacher (2008) by exploring how the dissemination of responsibility in clinical decision-making impacts patient outcomes. Our results suggest that when Clinical Decision Support devices are used in place of physician discretion, patients are less likely to penalize their physician for negative outcomes if the patient selects the use of a CDS. This suggests that there is less utility lost for bad outcomes when decisions are made by CDS devices, ceteris paribus.

“Lessons Learned from Implementing the Patient-Centered Medical Home” [First Author]

joint with John Wendland, Colette Carver, Hughes Cortney, and Sun Ki Mun, International Journal of Telemedicine and Applications.2012

The Patient-Centered Medical Home (PCMH) is a primary care model that provides coordinated and comprehensive care to patients to improve health outcomes. This paper addresses practical issues that arise when transitioning a traditional primary care practice into a PCMH recognized by the National Committee for Quality Assurance (NCQA). Individual organizations experiences with this transition were gathered at a PCMH workshop in Alexandria, Virginia, in June 2010. An analysis of their experiences has been used along with a literature review to reveal common challenges that must be addressed in ways that are responsive to the practice and patients’ needs. These are: NCQA guidance, promoting provider buy-in, leveraging electronic medical records, changing office culture, and realigning workspace in the practice to accommodate services needed to carry out the intent of PCMH. The NCQA provides a set of standards for implementing the PCMH model, but these standards lack many specifics that will be relied on in location situations. While many researchers and providers have made critiques, we see this vagueness as allowing for greater flexibility in how a practice implements PCMH.

Under Construction

Present Research:

“Payment Scheme Self-Selection in the Credence Goods Market: An Experimental Study” joint with Bejarano, Hernán, and Stephen Rassenti

Given heterogeneity in expert behavior across payment schemes in credence goods markets, it becomes important to understand the consequences of payment scheme selection. To study the effect on customer well being of expert self-selection, we recruited subjects to participate in a real-effort credence good laboratory market. Experts were either randomly assigned or faced with the choice of three payment schemes: fee-for-service, salary, and capitation. We found that experts who selected fee-for-service payment resulted in customers with significantly worse outcomes in comparison with experts who had been randomly assigned to fee-for-service. In contrast, experts who selected salary payment did not change customer outcomes relative to those who were randomly assigned.

The Impact of a Merit-based Incentive Payment System on Quality of Healthcare: An Artefactual Field Experiment joint with Noel M. Arring, Janet O’Brien, Katherine Markiewicz, Katherine S. Peterson

Despite their popularity, studies of merit-based incentive payment schemes have not demonstrated that outcome-based payment is associated with consistent improvement in performance or decline in costs of care (Emmert et al., 2012, Gillam et al., 2012; Rosenthal et al., 2006; Werner et al., 2011). The failure to find significant and consistent associations is likely due to the fact that policy changes to financial models are difficult to study in real-world contexts. Natural experiments or field studies typically do not allow the researcher to distinguish between the effects of implicit and explicit incentives, to adapt for measurement error, to implement exogenous changes to the models, or directly measure unintended consequences (Cox, Green, Hennig-Schmidt, 2016). Hence, novel research methods are necessary to isolate the potential impact of the proposed finance reform in the healthcare industry.

To study the potential impact of merit-based incentive payment schemes on practitioner behavior, we used economic experiments that leverage healthcare simulations with patient actors. We recruited practicing primary care physician assistants and nurse practitioners to participate in a medical simulation. The providers were asked to evaluate standardized patients (performed by actors) and develop diagnostic and treatment plans for each. Treatments in the experiment varied by incentive scheme. Providers were assigned to either a control group or merit-based incentive payment system (MIPS) group. In the control group, providers were paid a flat rate for participating in the experiment. Under MIPS, providers were paid a (lower) flat rate plus a bonus for each of the self-reported incentivized outcome measures that they satisfied. This approach allowed us to implement exogenous changes to providers’ incentives within a controlled environment. Measurements of patient satisfaction, standards of care, and adherence to the incentivized outcome measures were collected and compared across study groups.

Within our sample, we found that the MIPS increased the number of incentivized outcome measures met; however, the overall quality of care was lower for the MIPS group. Specifically, practitioners paid under MIPS had lower standards of care in collecting patient histories, conducting physical exams, and providing summaries of patient encounters. The MIPS group also had lower patient satisfaction scores. Further, practitioners paid under MIPS were more likely to inappropriately order the screening tests described in the PQRS measures. For example, practitioners paid under the MIPS were more likely to prescribe mammograms and colonoscopies for a patient under the age of 50, (i.e., outside the recommended age group).

This is the first study to use health care simulations to study a policy change in financial models. This approach allows us to directly measure unintended consequences of an outcome-based payment scheme in a controlled environment. In our study, we confirm economic predictions and find that practitioners respond to outcome-based payment by diverting resources from unrewarded actions (standards of care) to rewarded actions (incentivized outcome measures) (Holmstrom and Milgram 1991, Pendergast 1999, Gravel et al 2010).

Under Construction

Future Research:

I plan to continue examining the key variables of physician decision making induced by intrinsic and extrinsic motivations. My approach to exploring these influences is multifaceted. I plan to continue using my real-effort experiments as a foundation for my research and then expand on the experimental design so that I can collect telling data regarding the impact of new variables on agent decision making in a series of laboratory experiments (e.g., repeated games, patient selection, physician selection, etc.). Each new variable introduced to the experimental design will bring the approximation of the healthcare industry closer to reality, while allowing a direct measure of the impact of each variable.

Based on the results of this series of experiments on physician payment structures, I will be able to provide insight into the optimal physician payment structure. The optimal payment structure balances quality of care with the cost of care. With this information in hand, I will team up with medical schools or local healthcare providers to test the efficacy and efficiency of the novel payment structures in the field. During my time at both the University of Delaware and Virginia Tech I have developed relationships with health care providers and local medical schools in the interest of this project. I will use these valuable network connections and the networking experience gained as a springboard for establishing new contacts in the healthcare industry. The benefits of these relationships are twofold: they provide invaluable feedback on incentive structures and implementation, and they offer new venues to test payment scheme efficacy. Through collaborations with the healthcare industry, we can design and implement new, efficient payment mechanisms that optimize patient outcomes.


Teaching Awards:

Graduate Instructor of the Year, 2011
Department of Economics, Virginia Tech

Press Coverage of Teaching:
“Interactive Classroom” UDaily online edition, October 26, 2012

Courses Taught:

Arizona State University
Fall 2016: Economics for Health Majors, Health Economics

Fall 2015: Health Economics (Masters), Biostats (Masters)

Fall 2014-Spring 2015: Dirctor of Capstone Project for the Masters in the Science of Health Care Delivery

Shiela Lokareddy (MS, SHCD); Jon Patterson (MS, SHCD); Ryan Greiger (MS, SHCD); Kyle Jahn (MS, SHCD); Gabrielle Knight (MS, SHCD); Azra Ariff (MS, SHCD); Alexandra Douglas (MS, SHCD); Nathanial Howard (MS, SHCD); Jonathan Underwood (MS, SHCD); Anjali Agrawal (Honors UG, Nutrition)

University of Delaware
Fall 2012, Spring 2013: Honors Principles of Microeconomics

Spring 2012: Principles of Macroeconomics

Summer 2012–Spring 2013: Money and Banking

Fall 2013: Intermediate Microeconomic Theory

Spring 2014: Honors Colloquium: Behavioral Economics Honors Money and Banking

Virginia Tech
Summer 2009, Fall 2009 and 2011, Spring 2011: Principles of Microeconomics

University of Delaware Student Comments
[selected from end of the year teaching evaluations]:

• [Dr. Green] challenged the class with questions and demonstrations on the board that required the students to really think about and apply the concepts discussed in class.

• [Dr. Green] regularly interjects personal stores / examples of economics in action.

• [Dr. Green] gets the class thinking beyond just the concepts presented in the textbook.

• Her use of technology through research days reinforced the material and showed her willingness for progression in teaching methods.

• I thought Dr. Green did a good job of engaging the class by balancing lecture and discussion. The research days were also particularly helpful.

• Dr. Green is so excited and positive and she really made class fun. She also draws excellent graphs. I really liked that we had a small class and she was able to engage us all and make an economics class bearable.

• Dr. Green's use of the iPad to display notes was really helpful. Notes were easy to read and well organized. It is obvious she knows a lot about her field and tries very hard to apply it to our lives.

• Dr. Green clearly knows the material.

• [Dr. Green] Used real world examples effectively and made the material understandable

• Dr. Green is by far one of the best teachers I have had so far at UDel. She is organized and explains the material thoroughly and in a way that is easy to understand.

• The instructor helped us learn the concepts by showing us graphs and real world examples of economics, which I thought was very helpful. The graphs that the instructor drew made me see the demand and supply for markets. The instructor was very passionate about the subject and she was always willing to answer questions in class.

• Favorite class of the semester, mostly because of Dr. Green's teaching.

• I loved how organized this class was, and it really helped me to understand the information better.

• [Dr. Green was] passionate about the subject; entertaining - I enjoyed coming to class.

• She was always excited to start class and explained things further and effectively if someone asked.

• She was always very enthusiastic about the material and made herself readily available with answering any questions we may have had. Although a short period, I learned a lot from her. By coming to class and filling out her power points and by reading the textbook, I was able to fully absorb the material at hand. I also thought her research days were a great choice because it gave the students a time to actively apply the concepts. In her lectures she also accompanied the terms or concepts with examples, which definitely helped reinforce the material. She did a great job!

• Great. She's nice, fair, and really clear with the way she teaches. Notes are clear and easy to study from. Enthusiastic about econ.

• Dr. Green was a great professor. She made the topics very clear. The research days really helped as hands on examples for the material.

• Dr. Green was an awesome teacher and really nice person. I enjoyed this class and Econ is not one of my strong subjects.

• She's very dedicated and wants students to understand the course not just to pass her exams.

• Professor Green is an outstanding teacher. She makes Econ an informative yet enjoyable class.

• Professor Green was very nice and was always open to questions and discussions. She knew the subject well and provided good examples.

Extra Curricular Activities:

As with any academic, I strive to for a healthy balance between my research, teaching, and extra curricular activities.

While in graduate school, I started running as a form of “motion therapy”. I ran my first 10k in my second year of my PhD program and have since completed several other races including my first half marathon in the fall of 2012 [the hilly Runner’s World Half in Bethlehem, PA].

My passion for running eventually spilled over to swimming and cycling. I have completed 3 Sprint and 2 Olympic Triathlons. Perhaps one of the most gratifying of my accomplishments was beating my older brother in an Olympic Triathlon this past summer. My personal goal is to complete a marathon and a century ride (my longest bike ride to date is 92 miles).

I also enjoy hiking and have trekked several mountains up and down the east coast. My most recent victory was climbing Mount Washington via Huntington’s Ravine. Huntington’s Ravine is noted as the most difficult trail in the White Mountains and it lives up to its name.

Of course one must balance exercise with a healthy amount of culinary experimentation. Over the past couple of years I have sought to find the optimal recipe for several baked goods.

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