家戶之住宅選擇模型與住宅之家戶競爭模型實證比較分析

The Empirical Comparison on Housing Choice Models and Household Bid-Rent Models

在住宅市場上，當住宅達成交易之前，家戶必須在各可能之住宅替選方案中進行選擇。此稱之為家戶之『住宅選擇』。然而，另一方面，同一住宅亦可能面臨來自不同家戶之競價，並由出價最高者獲得。此稱之為住宅之『家戶競爭』。當交易達成時，此兩個現象理論上應是存在於同一住宅市場之兩個不同的解釋面向。本研究嘗試透過多項logit模型之選擇決策理論，對此兩個現象進行實證分析，分別建立了家戶之『住宅選擇』模型及住宅之『家戶競爭』模型。其中家戶之住宅選擇模型，以住宅方案所帶給家戶之消費效用函數為基礎，建立了McFadden logit選擇模型。而住宅之家戶競爭模型，則以各家戶對住宅之競價函數為基礎建立競爭模型。此為Ellickson（1981）所建立之模型。本研究以同一住宅市場之交易資料進行實證比較，並分別推算了兩個模型之剩餘所得彈性。經以台南都市地區民國88年購置新建大樓的家戶樣本進行實證。其結果顯示，在住宅選擇模型中當家戶之剩餘所得增加時，家戶之住宅消費傾向於高品質住宅。此與家戶競爭模型中，家戶競爭行為的改變結果一致。

Two choice decision models were empirically compared in the study. The first model is the housing choice decision faced by households. Based on the utility measurement of housing consumption, household chooses the one with maximum utility among the housing alternatives. The model is well known as McFadden's logit model. The other model is the household's bid auction decision on the given housing unit. Facing a housing unit with given attributes, every household offers the bid price which is willing to pay according to the household's socioeconomic characteristics. The success of a housing transaction ill the market implies a choice match of a household's housing choice and the household's bid auction on the same housing unit. To compare the two models, we computed the elasticity of choice probability with respect to the household's remaining-income, which is computed by the household income net off the housing consumption cost. Ill this study, empirical data is selected from the transaction survey of newly constructed housing in Tainan area, in 1999. Our results indicated that the increase in household's remaining-income, increases the choice probability on high quality housing while reducing on the low quality housing. The finding is consistent in both models.