Free trial is a widely used business strategy that takes advantage of information asymmetry. However, evidence on what we can learn and how rapidly we can learn from a free trial of health care is limited. This study evaluates the effect of a free trial of eyeglasses on children's 8 items of perception related to eyeglasses use. An evaluation was conducted alongside a cluster-randomized controlled trial involved 832 myopic children from northwest rural China. A total of 428 myopic children from 42 schools were randomized to receive free eyeglasses, and 404 myopic children from 42 schools were randomized as control group. We find that the perceived costs and benefits of eyeglasses use and the perceived timing of wearing eyeglasses at the appropriate time can be learned from a free trial of eyeglasses. Compared with the control group in the long run, 5.6 percentage points more children in treatment group agreed that wearing eyeglasses was attractive, 16.5 percentage points more children agreed that wearing eyeglasses is helpful to academic performance, and 7.9 percentage points more children agreed that children with vision problems should wear eyeglasses. Due to the effects of a free product and the time to learning from experience, the magnitude of the impact of a free trial changed over time. We also find that the indirect experience, such as a vision protection course, cannot change children' perceptions about the cost or benefits of eyeglasses use. The findings imply that children can learn significantly from the experience of a free trial of eyeglasses. A free trial is an effective strategy to solve the information asymmetry problem for health care. The first pair of eyeglasses of children can be one-off subsidized to trigger demand for eyeglasses use.
Keywords: experience attributes; eyeglasses use; free trail; information asymmetry; rural China.