Intervention(s)
The following description refers to the baseline treatment (which will be labeled BB-complex). We invite subjects on Prolific to an online experiment which consists of two parts. The first part is a survey in which we elicit demographic information (age, gender, education), online labor supply, online shopping experience, as well as measures of cognitive ability, trust, risk and time preferences. After the survey, we describe the second part, which consists of an experimental shopping task.
In the shopping task, subjects have to purchase a hypothetical book (HB). They will not actually purchase a book, but their earnings in the shopping task increase in the price savings that they realize. There are several sellers that offer the book. If a subject purchases HB from at the total price p, then her payoff in the shopping task is 15 – p USD.
In the baseline treatment, the total price consists of four partial prices that we call base price, shipping fee, delivery time costs, and seller rating costs. The total price is the sum of these partial prices. Each seller offer defines values for these partial prices.
Upon starting the shopping task, participants first see the overview webpage. This webpage does not only display HB, but also other books (by design, it is not possible to purchase any other book). In the baseline treatment, there is a “buy box”: Participants see the price vector of the top-ranked seller and can directly purchase the book from it by clicking on a button. Alternatively, they can click on a button called “All buying options”, in which case they enter the price comparison webpage. This page shows the offers of all 12 sellers. Both the overview and the price comparison webpage are designed like a generic online retail platform so that subjects have an intuitive understanding how they work. On the price comparison webpage, sellers are ordered according to the sum of the last three entries in the price vector (shipping fee, delivery time costs, seller rating costs), from lowest to highest value.
Subjects can purchase from the top-ranked seller on the overview webpage through the buy box or they can purchase from any seller on the price comparison webpage by clicking on a “Buy” button next to the corresponding seller’s price vector. Upon clicking on such a button, subjects need to confirm their choice. After confirming a choice, the shopping task is completed. If they do not trade with any seller, their payoff in the shopping task is zero.