A Service of Leibniz-Informationszentrum econstor Wirtschaft Leibniz Information Centre Make Your Publications Visible. zbw for Economics Halla, Martin; Liu, Chia-Lun; Liu, Jin-Tan Working Paper The Effect of Superstition on Health: Evidence from the Taiwanese Ghost Month IZA Discussion Papers, No. 12066 Provided in Cooperation with: IZA – Institute of Labor Economics Suggested Citation: Halla, Martin; Liu, Chia-Lun; Liu, Jin-Tan (2019) : The Effect of Superstition on Health: Evidence from the Taiwanese Ghost Month, IZA Discussion Papers, No. 12066, Institute of Labor Economics (IZA), Bonn This Version is available at: http://hdl.handle.net/10419/193360 Standard-Nutzungsbedingungen: Terms of use: Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Documents in EconStor may be saved and copied for your Zwecken und zum Privatgebrauch gespeichert und kopiert werden. personal and scholarly purposes. 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Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, If the documents have been made available under an Open gelten abweichend von diesen Nutzungsbedingungen die in der dort Content Licence (especially Creative Commons Licences), you genannten Lizenz gewährten Nutzungsrechte. may exercise further usage rights as specified in the indicated licence. www.econstor.eu DISCUSSION PAPER SERIES IZA DP No. 12066 The Effect of Superstition on Health: Evidence from the Taiwanese Ghost Month Martin Halla Chia-Lun Liu Jin-Tan Liu JANUARY 2019 DISCUSSION PAPER SERIES IZA DP No. 12066 The Effect of Superstition on Health: Evidence from the Taiwanese Ghost Month Martin Halla Johannes Kepler University Linz, CDECON, IZA and Austrian Public Health Institute Chia-Lun Liu Lehigh University Jin-Tan Liu National Taiwan University and NBER JANUARY 2019 Any opinions expressed in this paper are those of the author(s) and not those of IZA. Research published in this series may include views on policy, but IZA takes no institutional policy positions. The IZA research network is committed to the IZA Guiding Principles of Research Integrity. The IZA Institute of Labor Economics is an independent economic research institute that conducts research in labor economics and offers evidence-based policy advice on labor market issues. Supported by the Deutsche Post Foundation, IZA runs the world’s largest network of economists, whose research aims to provide answers to the global labor market challenges of our time. Our key objective is to build bridges between academic research, policymakers and society. IZA Discussion Papers often represent preliminary work and are circulated to encourage discussion. Citation of such a paper should account for its provisional character. A revised version may be available directly from the author. IZA – Institute of Labor Economics Schaumburg-Lippe-Straße 5–9 Phone: +49-228-3894-0 53113 Bonn, Germany Email: [email protected] www.iza.org IZA DP No. 12066 JANUARY 2019 ABSTRACT The Effect of Superstition on Health: Evidence from the Taiwanese Ghost Month* Superstition is a widespread phenomenon. We empirically examine its impact on health- related behavior and health outcomes. We study the case of the Taiwanese Ghost month. During this period, which is believed to increase the likelihood of bad outcomes, we observe substantial adaptions in health-related behavior. Our identification exploits idiosyncratic variation in the timing of the Ghost Month across Gregorian calendar years. Using high- quality administrative data, we document for the period of the Ghost Months reductions in mortality, hospital admissions, and births. While the effect on mortality is a quantum effect, the latter two effects reflect changes in the timing of events. Efficient public health policy should account for emotional and cultural factors. JEL Classification: I12, D83, D91, Z12 Keywords: superstition, false beliefs, health, risky activities, health-care utilization, mortality, fertility, birth outcomes Corresponding author: Martin Halla Johannes Kepler University of Linz Department of Economics Altenbergerstraße 69 4040 Linz Austria E-mail: [email protected] * For helpful discussions and comments we would like to thank seminar participants at the Hungarian Academy of Sciences (Centre for Social Sciences, RECENS) and the University of Hohenheim. The usual disclaimer applies. A Web Appendix available on the corresponding author’s website provides further results referenced in the paper. 1 Introduction Historically, medicine was closely associated with superstitions, magic and religion. The Greek physician Hippocrates laid the foundation for a rational approach to medicine. While modern scientific medicine rejects any supernatural origin of disease, many patients still believe in supernatural powers and superstition, or have severe misconceptions about the origin of certain diseases and the effectiveness of treatments. For instance, the believe that witchcraft can cause and heal diseases is widespread within developing countries in general, and in Africa in particular (Tenkorang et al., 2011). One recent phenomenon in high-income countries is the surge in the opposition to vaccines. The so-called \anti- vaccine movement" is fueled by misconceptions and myths about immunizations (Chang, 2018; Hussain et al., 2018; Oster, 2018). Despite the pervasiveness of such wrong beliefs, empirical evidence quantifying its impact on health is scarce. In this paper, we estimate the impact of superstition on health-related behavior and health outcomes. Our research design is based on the so-called Ghost Month. In Taiwanese culture, the seventh lunar month is Ghost Month. According to legend, during this month, the gates of the afterlife are opened, and ghosts roam the living world. The presence of the ghosts is believed to increase the risks of accidents and cause a higher likelihood of bad outcomes in general. Therefore, believers of this legend try to avoid a number of activities, such as traveling, swimming, leaving the house after sunset, major social events, major purchases, and supposedly even elective surgeries. According to survey data, about 72 percent of all Taiwanese participate in the Ghost Month festival, and about 66 percent believe that ghosts that are not offered any worship will wander around.1 There are several potential channels through which the Ghost Month may affect health. All channels are linked to the adaption of health-related behavior. The most effective adaption would be a self-enforced restraint from (or avoidance of) certain social or eco- nomic activities. Depending on the nature of these activities the effects on health can be either positive of negative. The avoidance of activities involving risks or causing stress may improve health. In contrast, adaptions in the domain of health-care utilization may be detrimental. If followers avoid or postpone health-care services (such as surgeries or births), they may jeopardize their health. The followers' adaptions may also generate spillover effects on others including non-followers. Other patients could be affected by variation in hospital occupancy rates caused by followers. Or, on a macro-level, a reduc- tion in the overall volume of traffic (and in related pollution) may have positive effects on the population at a large. We have access to high-quality administrative data, which allows us to test the effect of the Ghost Month in different domains. First, we have access to cause-specific mortality 1About 20 percent believe in the latter statement \yes, very much", and about 46 percent believe \yes, somewhat". All figures are based on data from the Taiwan Social Change Survey. Details are provided in Section2. 2 data. These allow us to infer on changes in activities associated with certain risks (such as driving). Second, we can utilize information on hospital admissions to study health- care utilization. Third, we use birth certificates to examine a potential effect on fertility and children's health at birth. We aim to identify an intention-to-treat (ITT) effect of the Ghost Month, without relying on the actual behavioral adaption due to superstitious beliefs. To identify this causal effect, we exploit the idiosyncratic timing of the Ghost Month. The exact date of the Ghost Month is determined by the lunar calendar, which is based on cycles of the lunar phases. Since the lunar and the Gregorian calendar are not fully synchronized, the exact date of the Ghost Month varies in the Gregorian calendar over years. For official and business purposes, Taiwan has adopted the Gregorian calendar for the longest time. The traditional lunar calendar is only used to define the dates of such festivals. Our estimation strategy is to identify the behavioral consequences of the Ghost Month (in daily data), while controlling for Gregorian calendar day and year fixed- effects. Thus, our identifying assumption is that the variation in timing of the Ghost Month across Gregorian calendar years is not correlated with unobserved determinants of our outcomes.2 Our analysis provides evidence that the Ghost Month affects mortality, the timing of health-care utilization, and fertility.