Essays on Market Dynamics and Frictions

by Saara Hämäläinen

Institution: University of Helsinki
Department: Department of Economic and Political Studies, Economics
Year: 2015
Keywords: taloustiede
Record ID: 1136143
Full text PDF: http://hdl.handle.net/10138/154160


Our thesis has three individual papers and an introduction. It contributes to dynamic price and search theory. The first paper deals with the classic problem of trading under asymmetric information. The other two analyze retailing strategies that help lock in buyers by creating in-store frictions. In the first paper, we investigate welfare and equilibrium trading in a decentralized search market with asymmetric information and bilateral communication opportunities. Sellers and buyers meet randomly and pairwise and view a shared signal of the seller's quality. In the following signaling game, the sellers can either rely on this costless signal (pool) or costly signaling (separate). We observe that, although the average market quality is high, additional information is not generally welfare improving. All equilibria are inefficient. Contrary to the usual tradeoff between price and liquidity, we find that the signals can help sustaining stationary Markovian equilibria where higher quality is traded faster. In the second paper, we construct a novel search model that features in-store frictions and equilibrium price dispersion both within and across stores. The frictions originate from the gradual arrival of price information within stores and the existence of deadlines for buyers. We show that sellers have an incentive carry several similar items and generate price variation among these items to amplify the existing search frictions and create barriers to switching in an environment where none exist initially. It also helps them to discriminate better between buyers, who end with diverse degrees of price information. As the number of items in stock expands, sellers can extract more profits. In our third paper, we develop a price search model that features endogenous frictions in a duopolistic environment. These frictions originate from the gradual arrival or price information within stores and the existence of deadlines for buyers. We show that both sellers have a strategic incentive to generate frictions. There exists exactly two equilibria with a unique asymmetric pattern: a prominent seller, whose expected price is higher but the in-store frictions lower, and a non-prominent seller. The buyers are divided exactly equally into informed and uninformed consumers, and into those who fail to find anything. Under the Poisson process, this surplus loss is about 6 %. Väitöskirja kuuluu sovellettuun peliteoriaan, tarkemmin sanottuna dynaamiseen hinta- ja etsintäteoriaan. Kokonaisuus sisältää yhteenvedon ja kolme erillistä paperia. Ensimmäisen paperin lähtökohtana on klassinen asymmetrisen informaation ongelma, jossa myynnissä on sekaisin erilaatuisia hyödykkeitä. Toinen ja kolmas paperi analysoivat myyjien strategioita, joiden tarkoitus on lievittää hintakilpailua, perustuen hinnanetsinnän tehokkuuden heikentämiseen. Kontribuutiot ovat teoreettisia eli niissä lähdetään tietyistä luontevista oletuksista koskien myyjiä, ostajia ja markkinaympäristöä. Näistä sitten dedusoidaan jotain uutta ja kiinnostavaa…