Consumer willingness to pay for a pharmaceutical disposal program in Serbia: A double hurdle modeling approach Milica Paut Kusturica a,⇑ , Svetlana Golocorbin-Kon b , Tijana Ostojic c , Milena Kresoja d , Marko Milovic a , Olga Horvat a , Tihomir Dugandzija e , Nada Davidovac f , Anica Vasic g , Ana Tomas a a Department of Pharmacology and Toxicology, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia b Department of Pharmacy, Faculty of Medicine University of Novi Sad, Novi Sad, Serbia c Faculty of Technical Sciences, University of Novi Sad, Serbia d Institute of Economic Sciences, Belgrade, Serbia e Department of Epidemiology, Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia f Pharmacy Dona Pharm, Nis, Serbia g Green Pharmacy, Novi Sad, Serbia article info Article history: Received 7 September 2019 Revised 15 January 2020 Accepted 20 January 2020 Keywords: Pharmaceutical waste Unused medicines Household Medicine disposal Take-back program Willingness to pay abstract Proper collection and disposal of pharmaceutical waste from households can reduce the negative influence of medicines on the environment. The aim of this paper is to examine the current methods of disposal of unused medicines from households, as well as the willingness of Serbian residents to participate and bear the costs of an organized collection program. Moreover, this research aims to define factors contributing to an individual’s willingness to participate and pay for a medicine collection program. The survey included randomly selected patients older than 18 years visiting private pharmacies in the four largest Serbian cities. The questionnaire included information regarding the presence of unwanted medicines within the household, general medicine disposal practices, the likelihood to participate in a medicine take- back program, willingness to pay for a medicine disposal program (per prescription and per visit), impor- tance to the environment, and demographic variables from participants. Approximately 80% of surveyed respondents are very or somewhat likely to participate, however less than half of the respondents are will- ing to pay for the collection of their unused medicines. The factors that influenced willingness to partic- ipate are environmental awareness and income, while the factors affecting willingness to pay, are previously received advice about proper disposal, education level, number of unwanted medicines in the household and gender. The majority of Serbian people dispose unused medicines improperly, mostly into household garbage. Well-organized and easily accessible collection programs are essential in order to enable the general public to return unused medicines for proper disposal. Ó 2020 Elsevier Ltd. All rights reserved. 1. Introduction The presence of medicines in drinking water, as a result of con- taminated groundwater, rivers and lakes is a problem that will continue to grow as the population expands and more medicines are dispensed. However, the environmental importance and human health risk that this represents may not be known for years (Daughton, 2003; Leung et al., 2013). While medicines can enter the environment during the produc- tion process, consumption or disposal, improper disposal of phar- maceutical waste from households is considered one of the most important routes for the entry of medicines into the environment (Daughton, 2003; Schwab et al., 2005; Webb et al., 2003). The cur- rent literature data suggests that improper disposal of medicines is a global problem which plays a significant role in environmental contamination (Paut Kusturica et al., 2017; Tong et al., 2011). According to literature, the most common reason reported for not returning medicines to pharmacies or other collection sites is lack of information and awareness on the existence of available unwanted medicine collection schemes in the community (Fenech et al., 2013; Kruopiene and Dvarioniene, 2010; Sasu et al., 2012). Proper collection and disposal of medicine waste from the household can reduce the negative impact of medicines on the environment (Lubick, 2010). Organized collection programs of unused medicines are being implemented in many countries around the world enabling medicines to be collected at https://doi.org/10.1016/j.wasman.2020.01.029 0956-053X/Ó 2020 Elsevier Ltd. All rights reserved. ⇑ Corresponding author at: Hajduk Veljkova 3, 21000 Novi Sad, Serbia. E-mail address: milica.paut-kusturica@mf.uns.ac.rs (M. Paut Kusturica). Waste Management 104 (2020) 246–253 Contents lists available at ScienceDirect Waste Management journal homepage: www.elsevier.com/locate/wasman