This paper sets up a canonical new Keynesian small open economy model with nominal price rigidities to explore the impact of habit persistence and exchange rate pass-through on the welfare ranking of alternative monetary policy rules. It identifies three factors that can affect the welfare ranking: the degree of habit persistence, the degree of exchange rate pass-through, and labor supply elasticity. In contrast to the findings of De Paoli (2009a, 2009b), the analysis reveals a reversal in the welfare ranking of alternative monetary policy rules for unitary intertemporal and intratemporal elasticities of substitution, depending on the asset market structures of small open economies with external habit. The paper also finds that exchange rate pegging outperforms domestic producer price index inflation targeting at high degrees of intratemporal elasticity of substitution and external habit, regardless of asset market structures. Finally, the paper finds that exchange rate pegging outperforms domestic or consumer price index inflation targeting if the exchange rate is misaligned.