| 摘要: | 新開放總體經濟學(New Open Economy Macroeconomics，簡稱NOEM)結合不完全競爭市場特性，將跨期最適的個體經濟基礎融入總體經濟理論之中，構成完整的一般均衡分析模型，適用於探討政策變動對總體經濟環境的影響。本研究將採用新開放總體經濟模型，分別探討儲蓄率變動、政府支出與外國人在本國消費非貿易財等三項因素的總體經濟效果。
第一個議題，延伸Obstfeld and Rogoff(1995)理論模型，引入金融部門以探討儲蓄率發生變動對總體經濟效果的影響。研究發現，當本國提高儲蓄率，將排擠本國消費，使本國福利水準下降，但對匯率、物價、國內產出、貿易條件與外國消費皆產生正向影響。對世界總消費影響，則取決於本國規模，若本國為大國，提高儲蓄率，將衝擊世界總消費；若為小國時，對世界總消費影響不明顯。此結論或可說明美國近年儲蓄率連年攀升，全球景氣卻不斷衰退，致使美國難以成為全球中流砥柱之原因。
第二個議題，修改Betts and Devereux(1996, 2000)理論模型中對稱性依市定價(Pricing to Market，簡稱PTM)之設定，考量一個存在不對稱依市定價的經濟體系，假設家計部門與政府部門有相同的消費偏好，以探討政府支出對匯率動態之影響。研究發現，當一國政府支出增加，將排擠民間消費，造成實質貨幣需求減少，致使匯率上升。當兩國廠商皆以本(外)國貨幣進行定價時，若本國規模愈大，政府支出變動引起匯率波動幅度愈小(大)。此外，隨著商品間替代彈性與實質貨幣需求的邊際效用彈性愈大，政府支出變化會引起的匯率波動幅度愈小，且短期匯率波動程度將高於長期匯率波動，此即匯率的過度調整(overshooting)現象。
第三個議題，延伸Lane(1997)的小國理論模型，參考Chao、Hazari and Sgro(2004)的論點，在效用函數的設定中加入外國人至本國消費非貿易財產生社會外部性，並將貨幣以現金付現(cash in advance)方式融入模型，藉以衡量外國觀光客素質的影響。利用本研究所建構的小型開放經濟體系，即可探討觀光客來台消費，是否對台灣的長短期消費、產出與福利水準帶來外溢效果。研究發現，擴大外國人來台觀光的效果取決於觀光客素質與消費能力。若觀光客素質與消費能力低落，此些因素皆會使短期景氣刺激效果減弱，對福利產生不利影響；若觀光客素質提升，則結論將完全相反。此結論或可應用於擴大開放中國觀光客來台旅遊的政策，除了入境人數外，若要有效刺激景氣，政策亦需同時考量觀光客素質與消費能力等因素，例如開放自由行以吸引較高素質觀光客，帶來多元廣泛的消費商機，進而促進經濟繁榮。
New Open Economy Macroeconomics (henceforth NOEM) developed by Obstfeld and Rogoff combined the characteristics of an imperfectly competitive market and merged the inter-temporal optimization of micro-foundations into macroeconomics; thus constituted a general equilibrium model that is suitable to scrutinize the influence of policy changes to macroeconomics. This thesis used New Open Economy Macroeconomic frameworks to analyze the effects of exogenous changes such as savings rate, government expenditure and foreigners’ consumption of domestic non-traded goods and services.
Extending Rogoff and Obstfeld (1995) model to include financial sector, my first essay analyzes the influence of saving rate changes on macroeconomics. The result shows that when domestic savings rate rises, it will crowd out local consumption. However, it will have positive effects on the exchange rate, commodity prices, domestic output, terms of trade, and foreign consumption. The magnitude it will have on world consumption depends on the size of the market. If we consider the case of a superpower country with a big market, a rise of savings rate will have a significant impact on total world consumption. On the other hand, the influence will not be so significant if the country is a small one. This may explain why the continuous rise in the United States of America saving rates in recent years has led to an economic downturn globally.
The second essay modifies the symmetric market pricing assumption in Betts and Devereux (1996, 2000). We focus on the effect of government expenditure on the exchange rate dynamics under asymmetric market pricing in a two-symmetric-country specifiaction. Our results show that when government increases their expenditures, it will crowd out private consumptions and lead to a low demand for real money and higher exchange rates. If firms in both countries set pricing in their own currency, the influence of government expenditure on currency fluctuation is smaller, the bigger the domestic market scale is.
The third essay extends Lane’s (1997) and Chao, Hazari and Sgro’s (2004) models, to analyze the effect of foreigners consumption on domestic economy. The utility function in the model takes into account the externality effects caused by foreigners’ expenditure in domestic country. Regarding the demand for money, we use cash in advance approach to help us measure the effects of foreign tourists’ expenditure in home country. The small open economy model in the paper can be applied to find out the effects of tourists’ expenditure in Taiwan, especially the long run and short run effects on Taiwan’s consumption, output, and social welfare. Our study has shown that the effects of more visitors to Taiwan depend on their “quality” and spending capacity. If their “quality” and spending capacity are not high, the effect to boost economy will diminish over time. Its policy implication is that, in order to effectively revive the economy, tourist “quality” and spending capabilities maybe are two very crucial factors. For instance, we can promote free and independent traveler (FIT) policy since it is likely to attract visitors with high quality and spending capacity. |
