經濟波動與房地產交易之價量關係：搜索模型之應用Economic Fluctuations, Prices and Trading Volume in the Housing Markets: An Application of a Search Model

本文嘗試建構一個搜索媒合模型，討論房地產交易之價量關係。研究發現經濟不穩定，會影響買賣雙方進入市場決策，使市場交易趨於冷清，造成交易量萎縮。價格變動則視起始條件而定，若供給(需求)意願對交易量衝擊彈性小，供給(需求)意願下降，會使價格出現漲(跌)勢；反之供給(需求)意願對交易量衝擊彈性大，供給(需求)意願下降，反而會使價格出現跌(漲)勢。以上現象可以解釋房地產市場，逢經濟不穩定，市場交易冷清；經濟穩定，市場轉趨熱絡現象。經濟穩定有助於創造交易量，縮短買方、賣方搜索期限。訊息成本下降，有助於降低買賣雙方房價差距，使價格趨於基礎價格。

關鍵詞：搜索模型、隨機優勢、媒合模型、均數固定變異擴張、核函數

This paper constructs a search matching model to discuss the trading volume and price in relation to real estate transactions. We find that economic instability will affect the decisionmaking of buyers (sellers), and their willingness to trade in the market. Economic fluctuations will result in a shrinking trading volume. The price effect on the sell or buy decision depends on the initial condition. If the trading volume elasticity of intention to sell (buy) is less than 1,sellers (buyers) exiting the market will induce prices to increase (decrease). On the contrary, if the trading volume elasticity of intention to sell (buy) is greater than 1, sellers (buyers) exiting the market will induce prices to decrease (increase). These correlations can help explain why the real estate markets will become thick (thin) markets during an economic boom (bust).
Economic stability will help create trading volume and shorten the search duration of buyers and sellers. A decrease in transaction costs will help reduce the price gap between buyers and sellers, and the prices will tend to be fundamental values.

Key words: search model, stochastic dominance, match model, mean-preserving spreads,
kernel density function