在實際經濟社會中，我們常看到的一種現象是相同的商品往往有數種價 格 (price dispersion)，即使在十分接近完全競爭市場結構的商品亦然。自訊息經 濟學逐漸為人重視後，訊息不充分所造成的價格分散就成為被大多數經濟學者所 接受的主要理由之一，其他原因尚包含消費者搜尋成本(search cost)不同，生產成 本不同等諸多因素。本文利用台灣地區住宅市場資料對下列三項論點加以驗證: 第一，經消費者搜尋後的市場均衡價格之分散程度要小於沒有搜尋前的價格分散; 第二，搜尋成本增加時，價格分散會擴大;第三，廠商生產成本差異較大時，價 格分散亦較大。我們以售屋之訂價(list price)當成搜尋前之價格，成交價(transaction price)當成搜尋後之均衡價格，並將住宅區分成中古屋、成屋、預售屋、及自用、 租賃、及空屋等情況分別討論，結果我們發現上述約三項論點皆獲得驗證與支持。

　　　　　It is common to see different prices for a same commodity in different stores) even the market is near a perfect market. Informationincomplete is accepted by most economists as one of the reasons toexplain price dispersion. Some other common reasons are differentsearch costs and different production costs and so on. This paperapplies housing data in Taiwan to test the following three arguments: (1) The degree of price dispersion will be smaller when consumers do search in the market. (2) The price dispersion is largerwhen search costs increase. (3) As the differences of the productioncosts increase, the price dispersion increases, too. We use list pricesas the prices before search and the actural transaction prices as theprices after search, and we also separate the housing market intopre-sale houses, new houses) second-hand houses, owner-occupiedhouses, rental houses, and vacant houses. We find that the abovethree arguements are all supported by our data, both in the wholemarket and in all of the sub-markets.