@TechReport{iza:izadps:dp18745,
            	author={Cai, Xiaoming and Gautier, Pieter A. and Wolthoff, Ronald P.},
            	title={Platform-Controlled Search  and Distortions in Attention Allocation},
            	year={2026},
	month={Jun},
            	institution={Institute of Labor Economics (IZA)},
            	address={Bonn},
            	type={IZA Discussion Paper},
            	number={18745},
            	url={https://www.iza.org/index.php/publications/dp18745},
	abstract={Digital platforms allocate buyer attention across sellers that differ in quality and breadth of appeal. We study a monopoly platform that sets meeting rates between buyers and two seller types --- niche sellers whose high-quality good is valued by a fraction  of buyers and mass-market sellers whose good is valued by all. Sellers compete by posting prices à la Burdett and Judd (1983), so buyer surplus requires competition, while platform revenue requires seller rents. This difference creates a systematic distortion: as search capacity grows, the platform keeps high-quality niche attention just past the point where extra exposure stops creating rents and starts eroding them — its saturation point — and diverts the rest to mass-market sellers.  Applying the model to Amazon product search and Google passage-ranking data indicates that, for captive buyers, both platforms operate past the saturation point, with buyer-surplus losses of 63 and 44 percent of the planner’s benchmark, respectively. Allowing buyer participation to respond to the platform's recommendation strategy disciplines the platform and shrinks this loss.},
	keywords={two-sided markets;search frictions;recommendation systems;attention allocation;enshittification of internet},
            }