摘要
本論文主要在探討除了商業銀行政策之外，信用卡簽帳金額與循環信用餘額的變化是否也會受到貨 幣政策的影響。為了瞭解消費金融裡信用卡業務與總體經濟的相關議題，以Chen（2013） 所發展出具有銀行部門與準備金市場的一般均衡模型為基礎，建構一個包括銀行部門、準備金市場 、及央行依據通膨目標設定利率法則進行公開市場操作的總體經濟模型，探討諸如商業銀行循環利 率及央行改變目標通膨等外生變數與政策變數變動時，對簽帳金額與實質存款等消費金融變數的影 響。 經由本文比較靜態分析探討模型外生變數變動影響內生變數的方向及大小：無法得到解析解(analytical solution)的部分則藉由數值分析，進一步了解商業銀行循環利率及央行改變目標通 膨等外生變數與政策變數變動時，對簽帳金額與實質存款等消費金融變數的影響方向及大小。另外 ，為了要驗證上述分析結論不會因本文選取的基準數值大小而有重大改變，本文也進行了數值模擬 的敏感度分析，以確認本文數值分析的研究結論合理。 本文研究主要結論如下：1. 家計單位決定的還款比例會影響商業銀行決定放款的數量，商業 銀行會視還款比例高低而改變願意放款在簽帳金額的金額，因此進一步影響到均衡簽帳金額。本文 之比較靜態分析顯示，循環利率大於時間偏好率之下，隨著商銀願意放款在消費金融的信用卡簽帳 金額的增加的敏感度決策變數上升，透過使得家計單位還款比例增加，使得最後的信用卡簽帳金額 均衡增加。2. 商業銀行決策方面，由本文數值分析得知，均衡簽帳金額隨循環信用利率上升而減 少，但此趨勢之斜率遞減也顯示，均衡簽帳金額多到某程度時，隨信用利率上升使簽帳金額減少的 效果趨緩。3. 中央銀行決策之法定存款準備率越高，使得商銀持有超額準備之機會成本越高，因 此法定存款準備率越高使得均衡簽帳金額會減少。4.央行提升通貨膨脹目標亦會使得均衡簽帳金額 減少。
關鍵字
總體經濟因素；消費金融並列摘要
It is generally considered that credit card sales and credit card revolving balance are affected by banks’ decisions. This thesis sets up a model to investigate such a mechanism, and to study how credit card sales and credit card revolving balance are affected by monetary policies conducted by the central bank. In order to address the relationship between credit card sales and macro-economic issues, a macro model that consists of consumers, banking sector, reserve market, and the monetary authority is needed. In this thesis, we extend Chen (2013) in the sense that consumption through credit cards is incorporated into Chen (2013) framework that includes a banking sector, reserve market, and open market operation conducted by the central bank. We then study the effects of private banks’ revolving interest rate and target inflation rate on credit card sales and credit card revolving balance. Comparative static analyses are conducted in this thesis to study how endogenous variables of our model are affected by various exogenous variables such as private banks’ revolving interest rate and target inflation rate. For analytical solutions that we are not able to determine signs and magnitudes of certain exogenous changes, we conduct numerical simulations. To avoid potential problems of drawing conclusions based on parameters chosen in the simulation of the baseline model, various sensitivity analyses are also conducted to check robustness of our model. The main results of this thesis are as follow. 1. The equilibrium credit card sales rise with the portion of repaid that banks set for credit card consumers. 2. The equilibrium credit card sales rise with private banks revolving interest rate. However, such effects dampen as credit card sales increase. 3. The equilibrium credit card sales rise with the required reserve ratio. 4. The equilibrium credit card sales rise with the target inflation rate set by the central bank.