選舉賭盤之價格形成

Abstract

在效率資本市場的假說下，市場交易價格可以反應出市場中的所有資訊。本文指出選舉賭盤或是選舉證券市場(election stock market)的政治證券(political security)也是服從效率資本市場假說，其賭盤價格或政治證券價格也能反應出市場對於選舉的相關資訊。本文強調選舉證券市場的交易價格在理論與實證研究上，都能預測選舉結果，顯示效率資本市場假說再次獲得支持。雖然選舉證券市場政治證券價格能準確預測結果，但並不代表其價格都沒有套利空間存在。在投資人存在有政治偏好時，套利機會經常出現。但由於邊際投資人(marginal trader)的存在，使得選舉證券市場政治證券最後交易價格終能正確預測選舉結果。

Under the efficient markets hypothesis, the market price should be able to reflect all the information in the markets. In this paper, we further confirm the validity of efficient markets hypothesis by showing that the election gamble price or the price of the political security can effectively predict the election outcomes. Even though the election stock market can predict the election very precisely, there still exists arbitrage opportunity in the election stock markets. The wish-fulfillment phenomenon causes the traders to buy their favor candidates leading to bias of the market price. However, the marginal traders usually trade without wish-fulfillment bias to facilitate the efficiency of the market price.