“…The largest part of the literature on vertical differentiation has considered partial equilibrium models with consumers on one side and firms on the other (Amir, Jin, Pech, & Tröge, ; Anderson, de Palma, & Thisse, ; Choi & Shin, ; Li & Zhang, ; Mussa & Rosen, ; Wauthy, ). Workers have been integrated in a less abundant literature highlighting the role of skills in the product's quality (Bacchiega, ; Gabszewicz & Turrini, , ; Hili, Lahmandi‐Ayed, & Lasram, ). But even these papers consider partial equilibrium models with separate categories of agents (firms, workers, and consumers).…”