本文建立一個資本市場存在訊息不對稱的模型,比較政府課所得稅及課鑄幣稅融通其支出的優缺點。我們首先建立，在資本市場存在訊息不對稱之下，政府支出的比例決定了貸款人是否受到借貸限制（credit rationing），而借貸限制是否存在則進一步決定所得稅與鑄幣稅融通的相對優點。當借貸限制不存在時，鑄幣稅融通所得到的經濟成長率及通貨膨脹率皆高於所得稅融通。當借貸限制存在時，鑄幣稅融通有較高的通貨膨脹率及較低的經濟成長率。從社會福利的角度來看，當借貸限制不存在時，鑄幣稅融通優於所得稅融通；反之，則所得稅融通優於鑄幣稅融通。本文的結論調和了許多理論文獻,也與近期的一些實證文獻一致。

This paper compares the relative merits of alternative government financing in the presence of asymmetric information. We first establish that the share of government expenditure determines whether or not credit is rationed, which in turn plays an important role in determining the relative merits of monetary and income-tax financing. It is found that monetary financing leads to both higher inflation and economic growth than income-tax financing if credit is not rationed. If credit is rationed, however, monetary financing leads to a higher inflation rate but a lower growth rate than tax financing. In comparing social welfare, we find that monetary (income-tax) financing is better than income-tax (monetary) if credit is not rationed (rationed). Our results reconcile the pre-existing literature and are consistent with some empirical evidence.