With data covering 20 years, we test three different liquidity measures' explanatory power in explaining asset returns on the Swedish stock market, and if an illiquidity premium exists. After establishing whether an illiquidity premium exists or not, we test whether the asset pricing models CAPM and the Fama-French three-factor model can benefit from including a liquidity factor. We use t-tests and regressions to test the liquidity measures and whether our chosen asset pricing models benefit from including a liquidity factor. Our findings do not support the definition of an illiquidity premium for our liquidity measures Return to dollar volume, Turnover rate, and Zero trading days. We apply a common definition of the illiquidity premium, which is that the least liquid portfolio should outperform the most liquid portfolio. We do, however, find that liquidity can to some degree explain asset returns, and when constructing a liquidity factor and including it into our asset pricing models, their explanatory power increases. Therefore, liquidy still might be a variable one should consider when explaining asset returns. Both CAPM and Fama-French three-factor model becomes better when including liquidity, and the result is consistent in our robustness test where we divide our sample into subperiods.

自2000年來，學術界開始廣泛地討論系統流動性風險因子以及非流動性因子是否在資產評價上有重要的影響，尤其在最近的金融危機中，市場的流動性風險應該如何被衡量及量化也是實務上重視的課題。不同於傳統的市場微結構模型，著重在衡量個股的流動性以及非流動性，本文嘗試以系統流動性評價模型建構流動性風險因子及非流動性因子來衡量整體市場的流動性，並探討市場流動性如何應用在資產評價上。 在Lee, Lin, Lee, and Tsao (2006)研究中，嘗試分析台灣市場個別股票流動性的共同因素(common factor)，並已得到確切的結論。然而此一系統性的流動風險因子尚未應用在資產評價模型上。本文在建構市場的流動性以及市場的非流動性兩個因子之後，並用以評價市場的股票報酬，結果發現若以市場流動性因子評估，則持有對市場流動性衝擊(liquidity shock)具有高度敏感性的股票(Beta>0)並同時賣出低敏感性的股票(Beta<0)，將會得到顯著的異常報酬。另一方面，若以市場非流動性因子衡量，則持有非流動性較高的股票並同時賣出非流動性較低的股票，也會得到顯著的異常報酬。 / Market-wide liquidity drain has aroused grave concerns in the recent financial tumult and prompted a number of academics to query how much the liquidity risk is incorporated into the pricing of those assets that are blamed for the recent financial collapse. Though this market-wide liquidity risk factor has started being acknowledged as a key component of asset pricing models, it has not yet been applied to Taiwan’s financial market. Based on the commonality in liquidity is confirmed by Lee, Lin, Lee, and Tsao (2006) in the Taiwan’s stock market, this study is the first one to include systematic liquidity factor in asset pricing model. Two different dimensions are employed due to liquidity is an elusive characteristic to measure. This study intends to measure the degree of liquidity shock and illiquidity characteristic that afflicts Taiwan’s stock market by looking into temporary price changes accompanying the order flow in the lag period and the trading volume in the contemporaneous period. Stock excess return has always been considered a compensation for risk. This study also explores whether excess return reflects compensation of market-wide liquidity, and provides evidences that the premium for systematic liquidity shock factor and illiquidity factor in the Taiwan’s stock market are all significant.