An applicability test of the use of deposit-refund system for managing water-sachet litter in Ilorin, Nigeria

Abstract

This study used both quasi-experiment and contingent valuation survey to explore the applicability of deposit-refund system (DRS) to water-sachet litter management in Nigeria. In the experiment, a DRS was established to incentivize the participants to return emptied sachets of water. A contingent valuation survey of 454 sachet-water consumers selected using quasi-systematic sampling technique was conducted. Experimental results showed that the number of sachets returned by the experimental group – those subjected to DRS – was significantly greater than that of the comparison group – those not subjected to DRS. Logit regression results showed that refund size increased the odds of returning sachets by 42.0%. Increasing the redemption time decreased the odds of turning in sachets by about 16.0%. A one-minute increase in the time spent on redemption would result in about 2.4% decrease in the probability that participants would comply. Income decreased the odds of compliance by about 31.0%, while age reduced the odds of compliance by about 2.2%. These results imply that the DRS reduced water-sachet littering in the study area, and that income, refund amount, redemption time, age and perceived effectiveness of DRS influenced consumers’ compliance with DRS. Hence, an appropriate motivating DRS would reduce litter and its attendant problems, such as hygiene, plastic pollution, flooding, aesthetic loss, non-naturally degradable toxic compounds, degradation of natural habitat ant its endangered species. The government should, therefore, implement a DRS and set up recycling plants, or encourage private recycling firms, in order to accommodate used sachets that would end up piling up.