本研究主要探討在小型開放經濟體下的最適貨幣政策，主要以新凱因斯模型在完全資本市場的假設之下，探討資本稅的可行性對總體經濟變數的影響。開放經濟下由於外部扭曲(external distortion)的存在，完全穩定國內通貨膨脹的政策就並非最適。本研究發現當兩國商品的替代彈性趨於無窮大時，封閉和開放經濟之間的政策差異就會消失。
從數值分析結果來看，最適貨幣政策的設計主要取決於是否課徵資本稅。若資產交易所帶來的不效率可以透過課徵資本稅來抵銷，則在最適貨幣政策之下國內通貨膨脹的變動幅度較小；反之，若政府無法最適的調整資本稅，則國內通貨膨脹的波動幅度將較大。本文亦發現，過去文獻在探討最適貨幣政策普遍未考慮經常帳方程式的做法，可能會導致虛假的結果產生。

This paper analyzes the optimal monetary policy in small open economies featuring monopolistic competition and nominal rigidity. Due to the presence of the external distortion, the optimal monetary policy in a small open economy can deviate from its closed-economy counterpart in that complete domestic inflation stabilization is not optimal in general. The policy discrepancy between closed and open economies vanishes if the elasticity of substitution between domestic and foreign goods goes to infinity.

The numerical results suggest that the design of optimal monetary policy depends crucially on whether a corrective asset tax is available. If the inefficiency in asset trading can be eliminated by an asset tax the optimal monetary policy exhibits little volatility in domestic inflation. In contrast, the optimal volatility of domestic inflation becomes much greater when an asset tax is unavailable.

This paper also shows that the common practice that excludes the current-account equation from the optimal policy problem may lead to spurious results.

[1] Benigno, G. and B. De Paoli (2010), “On the international dimension of fiscal policy". Journal of Money, Credit, and Banking 42, 1523-1542.
[2] Benigno, P. and M. Woodford (2003), “Optimal monetary and fiscal policy: A linear-quadratic approach". In M. Gertler and K. Rogoff (Eds.), NBER Macroeconomics Annual 2003, pp. 271-364. Cambridge, MA: MIT Press.
[3] Benigno, P. and M. Woodford (2005), “Inflation stabilization and welfare: The case of a distorted steady state.". Journal of the European Economic Association 3, 1-52.
[4] Corsetti, G. and P. Pesenti (2001), “Welfare and macroeconomic interdependence". Quarterly Journal of Economics 116, 421-445.
[5] De Paoli, B. (2009a), “Monetary policy and welare in a small open economy". Journal of International Economics 77, 11-22.
[6] De Paoli, B. (2009b), “Monetary policy and under alternative asset market structures: The case of a ll open economy". Journal of Money, Credit, and Banking 41, 1301-1330.
[7] Galí, J. and T. Monacelli (2005), “Monetary policy and exchange rate volatility in a small open economy". Review of Economics Studies 72, 707-734.
[8] Rabitsch, K. (2012), “The role of financial market structure and the trade elasticity for monetary policy in open economies". Journal of Money, Credit, and Banking 44, 603-629.
[9] Ravennah, F. and C.E. Walsh (2012), “Monetary policy and labor market frictions: A tax interpretation". Journal of Monetary Economics 59, 180-195.
[10] Rotemberg, J.J. (1982), “Sticky prices in the United States". Journal of Political Economy 90, 1187-1211.
[11] Rotemberg, J.J. and M. Woodford (1997), “An optimization-based econometric framework for the evaluation of monetary policy ". NBER Macroeonomics Annual 12, 297-346.
[12] Schmitt-Grohé, S. and M. Uribe (2003), “Closing small open economy models". Journal of International Economics 61, 163-185.
[13] Taylor, J.B. (1993), “Discretion versus policy rules in practice". Carnegie-Rochester Conference Series on Public Policy 39, 195-214.
[14] Woodford, M. (2003), “Interest and prices: Foundation of a theory of a theory of monetary policy". Princeton, NJ: Princeton University Press.