Before revision:  In our set-up, the choices of friends act as exclusion restrictions in the stochastic variation of the subset of alternatives that each person considers at the moment of picking an option. They allow us to recover (from a sequence of observed choices) the ranking of preferences of each person , the attention mechanism , and the set of connections or nodes between the people in the network .
After revision:  In our set-up, the choices of friends induce changes in the distribution of the consideration sets. We exploit this variation to recover the ranking of preferences of each person , the attention mechanism , and the set of connections or nodes between the people in the network .