We build an analytical model à la Hotelling describing the process of e-substitution in the market for transactional mail. A generic firm sells a final good to customers, with each unit sold requiring one unit of communication between firm and customer, which can take the form of either letter...

The renegotiation of regulatory contracts is known to prevent regulators from achieving the full commitment efficient outcome in dynamic contexts. However, assessing the cost of such renegotiation remains an open issue from an empirical viewpoint. To address this question, we fit a structural...