b. S=100，r=6%，call=8，put=5，K=100，1 year left to maturity。是否有無風險套利機會? 你該如何做?寫得愈清楚愈好。(5 分)

2. a. S=100，r=6%，call=15，put=5，K=100，1 year left to maturity。是否有無風險套利機會? 你該如何做?寫得愈清楚愈好。(5 分)  

a. 選擇權的時間價值與內在價值永遠都會大於或等於零。(3 分)

b. 債券的存續期間都一定會小於或等於到期期間。(3 分)

c. 債券的曲度(凸性)都一定為正值。(4 分)

(一)短期將對經濟體系產生什麼影響？若政府未採取任何政策，長期又會有何影響？ 試以 AD-AS 模型繪圖說明之。（10 分）

(二)中央銀行可採取何種貨幣政策來刺激經濟以回到長期均衡？在何種情況下貨幣 政策將無效或受限制？試以 IS-LM 模型繪圖說明之。（10 分）

(三)政府亦可採取何種財政政策來刺激經濟？對民間投資有何影響？（5 分）

二、若政府稅額收入相同，試比較比例所得稅與線性累進所得稅，納稅者較喜歡繳納何 種稅？試以所得休閒模型繪圖說明之。（15 分）

三、若政府救濟金額相同，試比較負所得稅（negative income tax）與工資補貼（wage subsidy），受補助者較喜歡接受何種救濟？並以所得休閒模型繪圖說明之。（10 分）

⑴Vaccine opposition has ebbed and flowed over centuries. In the mid-1800s, people protested in the streets of England after the British government began requiring citizens to get the vaccination. Many opponents mistrusted doctors and were wary of a medical treatment they didn’t understand. For a long time in history, people treated these opponents as irrational and anti-progress — kind of a lunatic fringe. But there were good reasons to be leery of vaccines. In the early days, the closely related cowpox virus was used to immunize people against smallpox.（25 分）