There has been an increasing interest in the finance literature regarding the impact of transactions costs on US equity markets. The US empirical evidence indicates that transactions costs influence both trading volume (Atkins and Dyl (1997)) and asset returns (Amihud and Mendelson (1986)). Additionally, the theoretical finance literature also indicates that transactions costs affect equilibrium asset returns (Fisher (1994)). In this thesis we assess the impact of transactions costs on the UK equity markets, from four aspects. Firstly, we provide empirical support to the hypothesis that transactions costs affect the "holding period" of an asset in the portfolio of an investor. Secondly, we provide robust results showing that transactions costs affect equilibrium asset returns. Thirdly, we explain the variability of transactions costs with the use of information asymmetry, proxied by the variance of analysts' forecasts, in the spirit of Kim and Verrecchia (1994, 2001). Finally, we find that stock price and trading volume reaction to changes in the FTSE 100 list can be explained by liquidity effects, as proxied by the bid-ask spread. We provide overwhelming evidence, suggesting that transactions costs are important in UK equity markets.

我們利用「台灣地區中老年身心社會生活狀況長期追蹤調查研究」這份資料，以似無關迴歸(Seemingly Unrelated Regression)模型，探討老人的資產持有行為，發現：一般老年人口並不偏好持有股票，持有行為相當少見，但高教育、高所得、都市化地區（尤其是直轄市）的老人，可能分別因為高教育程度、所得效果影響、都市地區資訊流通快速等因素，使得這類型老人明顯較願意持有股票。 另一方面，在台灣，不動產扮演的角色特殊，傳統認為其與家族宗系連結，在持有行為上並非只從風險報酬觀點去看待，通常還與其他考量有關，因此在持有行為上有其特殊模式。 同時，我們也發現，老人婚姻關係的消解(dissolution)，例如離婚/分居，將對資產持有產生負面的財富效果影響，使得這類型老人各項資產的持有都顯著低於已婚/同居的老人；而健康情形越差的老人持有的不動產與存款也越少，應與此類老人有較高的醫療與保健支出，造成負面的財富效果有關。 除此之外，台灣老人平均而言，持有的不動產會隨年紀降低，但持有的存款會隨年紀而上升，主要與台灣老人隨著年紀上升，所得逐漸不足以維生，產生了反儲蓄(dissave)不動產的現象，有所關聯。我們認為台灣確實存在老人「以房養老」的現象。 最後，我們認為很重要的一點是，台灣老人資產的持有行為，並不是使用傳統的風險報酬概念就能解釋，我們必須考量其他可能因素，才能有效分析台灣老人所表現出來的資產持有行為。 / The general elders don’t prefer to hold stocks, but the elders of high-level education, the elders of high-level income and the elders in metropolis are more willing to hold stocks. Besides, the real estate plays a special role. People regard that it is linked up with the family or kindred. We also find out that the dissolution of relationship in elder’s marriage causes negative wealth effect on holding assets. The similar effect exists in much unhealthy elders. The elders hold less real estate as they getting older, but hold more stocks. It might due to that elders dissave their real estate. Finally, besides perspective of risk-reward, it might appropriate that think the behavior of holding assets in other view-points.