訊息搜索、信念形成與回饋效應

本文聚焦於市場摩擦下的訊息功能，探討訊息經由搜索、形成信念、行為決策及所引發的回饋效應。模型主要架構在Stigler (1961)、Mortensen and Pissarides (1994) 之搜索議價模型上，並利用Longhofer and Peters (2005) 之訊息選擇性偏誤模式，討論信息基礎之價格差異。基於訊息摩擦導致訊息選擇差異，訊息選擇影響信念，並透過決策實現於市場。搜索議價模式下，議價機制仍具分配、信念修正與制衡功能。市場若出現訊息與價格操縱現象，價格的訊息功能與議價機能失靈，會產生價格崩跌與泡沫兩種極端。當交易者悲觀，買方訊息與價格操縱力強於賣方，交易雙方保留價格逐步降低，使賣方受困於流動性陷阱；反之，當交易者樂觀，賣方較具訊息與價格操縱力，交易雙方保留價格逐步增加，使買方受制於價格泡沫中。

關鍵字

金融摩擦；信念；選擇性偏誤；搜索模型；流動性；隨機優勢

並列摘要

This article focuses on the information function under market frictions, and explores the information loops which trigger information search, the formation of beliefs, behavioral decision-making and feedback effects. The frameworks of search-bargaining models are based on Stigler (1961), Mortensen and Pissarides (1994), and the self-selected information bias model of Longhofer and Peters (2005) are applied to analyze information based price discrimination. Information selection behavior which affect investor’s beliefs and decision under information friction are self-fulfillment in the market. The market mechanism of searching bargaining model remains the market functions including bargaining, allocation, beliefs feedback and modification. However, market information and price manipulation phenomenon will result in information and pricing function failure and the market crash and price bubble. Under the pessimistic situation, the buyers will control the market when their bargaining and information dissemination are stronger than the sellers. The preservation prices of traders will reduce spirally, and sellers are caught in liquidity traps. Conversely, under optimistic situation, the sellers will have more information and price manipulation powers, the reservation prices of traders will become less, and the buyers are subject to the price bubbles.