Regis Renault has just published with Simon Anderson a new paper in the Review of Economic Studies entitled “Search Direction: Position Externalities and Position Auction Bias”. The paper is about firms’ competition when there is ordered consumer search. This is for instance the case with online ads where consumers visit firms sequentially according to a given search order. The paper develops a unified framework in which firms both set prices and compete for positions in the search order, allowing for several forms of product heterogeneity. It highlights how these characteristics generate position externalities that affect both firms’ pricing strategies and their incentives to bid for earlier positions. The analysis also compares the rankings that maximize firms’ profits with those preferred by consumers and studies whether standard auction mechanisms can implement these outcomes. The framework is general but it also has important applications for digital markets such as search engines and online platforms, where visibility and search order shape competition and consumer welfare.