隨著網路的發展，人們使用網路搜尋資料變得更加頻繁。搜尋引擎提供了人們能以更方便的方式，搜尋自己所想要的資料。而這樣的方便性，也讓人們有誘因在網路上搜尋自己所喜愛的商品或服務。隨之而起的比價網站，即為搜尋引擎的一種。比價網站成功地將消費者端與供應商端結合在同一個平台內進行交易。本文將探討在比價網站內，消費者、供應商與平台業者 (比價網站所有者) 之間的互動行為。其中，我們假設供應商只生產並銷售同質商品，並將其商品的廣告刊登於比價網站內。而消費者則選擇是否要透過比價網站進行消費。從本文的分析，我們發現平台內的競爭程度在三個族群 (廠商、消費者、平台業者) 的互動以及社會福利上扮演著重要的角色。我們更進一步地發現，平台之間的競爭可能會讓市場的資源分配變得更沒有效率。此外，由於平台之間的勾結會使平台業者有誘因增強平台內的競爭程度，平台間的勾結行為可能有助於提升整體市場的資源分配。Accompanied with the development of the Internet, people access information through the Internet more frequently. Comparison sites use different kinds of search engines, offer a convenient way for retailers and consumers to interact. We examine the interaction between comparison sites, retailers and consumer behavioral patterns. The retailers advertise and sell homogeneous products and the consumers choose to shop. This is done either through web based stores or physical stores. In this analysis, we find that the level of competition between retailers in a platform play a critical role in the behaviors of all three agents; the consumer, the retailer itself,and the comparison sites. Also our analysis will further explain the role of the social welfare effect. We also find that the competition between platforms may worsen the efficiency of the allocation of markets. However, the collusion between platforms has its positive effects to the whole market because platforms have a stronger incentive to raise level of competitiveness between retailers. Such incentive increases the efficiency of the allocation of markets.
