My research focuses on using economic theory and data to evaluate the consequences of public policies. Although most of my research has focused on topics related to health policy, I have published on a wide variety of topics. My goal in each paper has been to produce rigorous research that can be used to guide public policies. In this research statement, I highlight papers I have published answering questions from four policy areas: 1) health policy, 2) environmental policy, 3) counterterrorism policy, 4) international trade policy.
1.0 Health Policy
The majority of my health policy research has involved using discrete choice models to theoretically and empirically capture how individuals make choices between medical treatments or health-related policies (Verrill et al., 2017; Lewis et al., 2018; Moise et al., 2018; Cheung et al., 2020; Wood et al., 2020; Stewart et al., 2021; Kocher et al., 2022; Moor et al., 2022). In this section, I detail two of these papers that are representative of my work.
1.1 How can enrollment in clinical trials for inflammatory bowel disease treatments be increased? (Wood et al., 2020)
It is estimated that approximately 3.1 million Americans report having an inflammatory bowel disease (IBD) like Crohn’s disease or ulcerative colitis. According to ClinicalTrials.gov, almost 1,500 clinical trials are available to patients with IBD in the United States. However, most of these clinical trials will fail to enroll the required sample size. In fact, more than 50% of clinical research sites fail to achieve enrollment targets in clinical studies. This raises the question of how to improve clinical trial recruitment.
This study answered this question using a discrete choice experiment involving 949 inflammatory bowel disease (IBD) patients to quantify how changes in clinical trial attributes, like monetary compensation, can improve recruitment rates. We found that changes in monetary compensation have the biggest potential impact on recruitment rates over any other single attribute. For example, increasing monetary compensation for participating in the study by $2,000 over the life of a 1-year trial will more than double predicted recruitment rates (holding all other factors constant). Our results were published in Crohn's & Colitis 360.
1.2 Can U.S. lung allocation policy be captured by a discrete choice model? (Stewart et al., 2021)
Lung allocation decisions in the United States are made according to policies developed by the Organ Procurement and Transplantation Network, which is operated by the United Network for Organ Sharing (UNOS). When a deceased donor lung becomes available, these policies state how potential transplant recipients (candidates) are ranked. First, candidates are divided into one of six distance categories called “zones” based on how close their transplant hospital is to the donor’s hospital (e.g., Zone A includes candidates within 250 miles of the donor hospital, Zone B includes candidates between 251 and 500 miles of the donor hospital, etc.). Candidates in zones closer to the donor hospital (e.g., Zone A) are ranked above candidates in zones farther away (e.g., Zone B) because it’s generally preferable for transplant organs to travel shorter distances. Next, candidates within each zone are categorized and ranked based on other objective characteristics like medical urgency, blood type, etc.
This categorization approach has been used to successfully allocate lungs in the United States for decades. However, it can lead to undesirable organ allocations in “edge” cases. For example, even the most medically urgent candidate located 251 miles from the donor hospital would not receive the organ if a less medically urgent patient was 249 miles from the donor hospital. This limitation has led some policy analysts to suggest that a better system would be to award candidates points based on objective characteristics like distance and medical condition and then offer the organ first to the candidate with the most points. This “points-based” approach would therefore remove the barriers that create “edge” cases like the one above.
The purpose of this study, funded by UNOS, was to estimate an equation that could be used as the basis of this points-based system. Ideally, this equation would broadly approximate current lung allocation policy and only address edge cases. We achieved this goal by modeling lung allocations as if they were discrete choices made by an economic agent. This allowed us to apply conventional discrete choice modeling techniques, using all organ allocations data for 2018, to estimate statistical models affecting adult and pediatric lung allocation policies. Next, to see how well these models captured current lung allocation policy, we used these scores to predict what the candidate wait-list rankings would be compared to the current system. The closer the predicted rankings are to the actual rankings, the more confidence we have that the scores approximate current allocation policies. Overall, we found the equation we estimated produced rankings that closely matched the original ranks produced by the current lung allocation system.
Our results were published in BMC Medical Informatics and Decision Making in 2021. Since publication, the results of our study have been used by OPTN and UNOS as the basis for a new points-based lung allocation system that will replace the current system (OPTN, 2022).
2.0 Environmental Policy
2.1 Are reductions in U.S. fossil fuel use offset by increases in fuel use in other countries? (Wood et al., 2022)
Global crude oil markets are interconnected so that changes in crude oil use in any one country can influence the world oil price and, in turn, oil consumption in other countries. For example, suppose the United States implemented a policy to reduce its oil consumption and corresponding greenhouse gas emissions. Economic theory suggests this reduction in oil consumption will lead to lower global crude oil prices. This reduction in global crude oil prices could lead to lower retail fuel prices and greater oil consumption in non-U.S. countries. As a result, the reduction in U.S. greenhouse gas emissions could be partially offset by increased emissions in other countries—sometimes referred to as the global rebound effect.
In this paper, we explore the magnitude of the global rebound effect. Specifically, we empirically investigate the two theoretical predictions summarized above by quantifying: (1) how much changes in global crude oil prices influence retail prices for gasoline and diesel fuels, and (2) how much changes in global crude oil prices influence diesel and gasoline consumption.
To conduct this investigation, we use monthly retail fuel price and consumption data to estimate structural vector autoregressive (SVAR) models for 63 countries representing nearly 70% of global refined oil consumption. Next, we use these SVAR models to estimate: 1) retail fuel price elasticities with respect to changes in crude oil prices, and 2) fuel consumption elasticities with respect to changes in crude oil prices. We estimate these elasticities at both at a country-specific level and in aggregate.
Based on our analysis, we found that short-term gasoline prices and diesel prices do fall when global crude oil prices decrease. However, gasoline and diesel fuel consumption are not impacted by changes in global crude oil prices in the short run (i.e., the elasticity of fuel consumption with respect to changes in crude oil price is not statistically different from 0). This suggests that in the short-run country-specific policies can influence oil consumption without significant global rebound effects. Our results were published in Energy Economics, which is the premier field journal for energy economics (boasting an impact factor of 9.3).
3.0 Counterterrorism Policy
3.1 Are Americans willing to make tradeoffs between civil liberties and national security? (Finkelstein et al., 2017)
After the terrorist attacks of September 11, 2001, the U.S. government pursued a variety of new and often controversial counterterrorism policies. These policies imposed billions of dollars of monetary costs on U.S. taxpayers. They also imposed additional nonmonetary costs on those individuals who felt that their, or others’, civil liberties were restricted as a result of expanded government powers. Given the controversial nature of counterterrorism policy, the design and evaluation of effective policies would benefit from an improved understanding of the public’s willingness to accept the monetary and nonmonetary costs of specific policies in exchange for improved national security.
The purpose of this study was to quantify the extent to which individuals are willing to trade off civil liberties in exchange for increased security. We achieved this goal by conducting an online survey of 973 respondents. This survey included a discrete choice experiment where respondents were asked to choose between a series of hypothetical policies.
Our results suggest that self-identified liberals place a higher weight on policies that provide more protection of civil liberties/personal freedoms than self-identified conservatives or moderates. Liberals, for instance, were willing to accept higher terrorist risk to protect civil liberties than moderates and conservatives, and liberals had the strongest preferences, as measured by willingness to pay, for policies that placed the least restrictions on personal freedom and privacy. However, conservatives had stronger preferences for policies that allowed discretion in applying policies that might infringe on privacy and personal freedoms. These differences may reflect the greater trust conservatives have in the government not abusing power rather than conservatives placing less value on the protection of civil liberties. Our results were published in Contemporary Economic Policy.
4.0 International Trade Policy
4.1 How did China’s retaliatory tariffs impact the U.S. farm sector? (Zheng et al., 2018)
In April 2018, trade tensions between the United States and China began to escalate. Specifically, China proposed increasing import tariffs by as much as 25 percentage points on hundreds of U.S. agricultural commodities in response to an announcement the United States would increase tariffs on numerous Chinese imports. This dispute led to a surge of articles in the popular press on the potential impacts of these tariffs on U.S. farmers.
To help provide a deeper analysis on the trade policy impact, Choices Magazine (the principal outreach vehicle of the Agricultural & Applied Economics Association) organized a special theme issue on China’s retaliatory tariffs. For our contribution to this issue, we used a partial equilibrium trade model (known as the Global Simulation Model) to predict the impact of China’s retaliatory tariffs on producers of four major agricultural commodities—soybeans, cotton, sorghum, and pork. Based on our analysis, we predict that 1) prices of these commodities will fall by 0.6% (pork) to 10.6% (sorghum), 2) exports of these commodities to China will fall significantly (up to 83% in the case of pork) while exports to other countries will increase, and 3) U.S. producers will suffer significant losses due to the decline in exports and prices (soybean producers will lose $1.8 billion). In 2019, our paper, along with the other contributions to this special issue of Choices, received the Agricultural & Applied Economics Association’s Quality of Communication Award.
5.0 References
Cheung, Y. K., Wood, D., Zhang, K., Ridenour, T. A., Derby, L., St Onge, T., & Moise, N. (2020). Personal preferences for Personalized Trials among patients with chronic diseases: an empirical Bayesian analysis of a conjoint survey. BMJ Open, 10(6). http://dx.doi.org/10.1136/bmjopen-2019-036056
Finkelstein, E., Mansfield, C., Wood, D., Rowe, B., Chay, J., and Ozdemir, S. (2017). "Tradeoffs between civil liberties and national security: A discrete choice experiment." Contemporary Economic Policy, 35(2), 292-311. https://doi.org/10.1111/coep.12188
Kocher, E., Wood, D., Lim, S. C., Jackson-Morris, A., Kataria, I., Ngongo, C., & Mustapha, F. I. (2022). Community priorities for obesity prevention among low-income adults in Kuala Lumpur: a discrete choice experiment. Health Promotion International, 37(6), daac156. https://doi.org/10.1093/heapro/daac156
Lewis, M. A., Stine, A., Paquin, R. S., Mansfield, C., Wood, D., Rini, C., Roche, M., Powell, C.M., Berg, J.S., and Bailey Jr, D. B. (2018). "Parental preferences toward genomic sequencing for non-medically actionable conditions in children: a discrete-choice experiment." Nature: Genetics in Medicine, 20(2), 181. https://doi.org/10.1038/gim.2017.93
Moise, N., Wood, D., Kronish, I., Duer-Hefele, J., Davidson, K., Duan, N., St. Onge, T., Pu, T., and Cheung, Y.K.K. (2018). "Patient preferences for Personalized (N-of-1) trials: A conjoint analysis." Journal of Clinical Epidemiology. https://doi.org/10.1016/j.jclinepi.2018.05.020
Moor, S. E., Tusubira, A. K., Wood, D., Akiteng, A. R., Galusha, D., Tessier-Sherman, B., & Schwartz, J. I. (2022). Patient preferences for facility-based management of hypertension and diabetes in rural Uganda: a discrete choice experiment. BMJ open, 12(7), e059949. http://dx.doi.org/10.1136/bmjopen-2021-059949
Organ Procurement and Transplantation Network (OPTN). (2022, October 26). “Notice of OPTN Policy Changes: Establish Continuous Distribution of Lungs”. Retrieved December 13, 2022, from https://hrsa.unos.org/media/b13dlep2/policy-notice_lung_continuous-distribution.pdf
Stewart, D. E., Wood, D. W., Alcorn, J. B., Lease, E. D., Hayes, M., Hauber, B., & Goff, R. E. (2021). A revealed preference analysis to develop composite scores approximating lung allocation policy in the US. BMC Medical Informatics and Decision Making, 21(1), 1-11. https://doi.org/10.1186/s12911-020-01377-7
Verrill, L., Wood, D., Cates, S., Lando, A., and Zhang, Y. (2017). "Vitamin-Fortified Snack Food May Lead Consumers to Make Poor Dietary Decisions." Journal of the Academy of Nutrition and Dietetics, 117(3), 376-385. https://doi.org/10.1016/j.jand.2016.10.008
Wood, D., Kosa, K., Brown, D., Ehrlich, O. G., Higgins, P. D., & Heller, C. (2020). Preferences of Adult Patients With Inflammatory Bowel Disease for Attributes of Clinical Trials: Evidence From a Choice-Based Conjoint Analysis. Crohn's & Colitis 360, 2(1). https://doi.org/10.1093/crocol/otz048
Wood, D., Larson, J., Jones, J., Galperin, D., Shelby, M., & Gonzalez, M. (2022). World oil price impacts on country-specific fuel markets: Evidence of a muted global rebound effect. Energy Economics, 106024. https://doi.org/10.1016/j.eneco.2022.106024
Zheng, Y., Wood, D., Wang, H.H., and Jones J.P.H. (2018). "Predicting Potential Impacts of China’s Retaliatory Tariffs on the U.S. Farm Sector." Choices, 33(2), 1-6. http://www.choicesmagazine.org/UserFiles/file/cmsarticle_640.pdf