In the paper A Behavioral-Economics View of Poverty, Eldar Shafir explains:
“Minor situational details, referred to as channel factors can have great impact. The opening up of a channel (such as an a priori commitment, or a first step) may facilitate some behaviors, whereas other behaviors can be blocked by closed channels. In one classic study, college seniors were given persuasive messages about the value of an inoculation against tetanus. While the messages were effective at changing the students’ beliefs and attitudes, few actually took the step of getting a tetanus shot. By contrast, when other students received the same messages but were also given a map of the campus with the infirmary circled and asked to decide on a particular time, the percentage of students getting the innoculation increased by an order of magnitude.”
At our village eye clinics, more than half of the people who are screened and who need glasses fall in the category of “will purchase soon” (which is different than “needs but does not want”). People want to buy glasses “later”. Perhaps they need more time to think about it, need to consult a spouse or don’t have money with them. Regardless, between now and later, Shafir’s channel factors will get in the way – for the buyer and for the seller. Other parts of life become more pressing as time goes by. One of the things I’m working on is creating ways to reduce the barriers that prevent these prospective customers from getting their new glasses.