Which Method Should the Central Bank Choose to Estimate the Model Economy? A Korean Monetary Policy Example

To understand how the macro economy evolves, the central bank has two options in choosing how to estimate the economic model against actual data: one is to estimate each sector of the model piece-by-piece, and the other is to estimate the whole model altogether. This paper demonstrates the advantage for the central bank of estimating the whole model in terms of the estimation accuracy and the robustness of the resulting policy recommendations. For that aim, we construct a macro model for the monetary policy analysis of the Korean economy and estimate the model via the system approach and single-equation approach. We evaluate the data fits of the two estimation results and show that the fit of the system approach is far better than the other and comparable to other methods such as vector autoregressions. It is also shown that, if the two estimated models are equally likely, conducting the policy tailored for the model estimated by the system approach delivers better stabilization results for the Korean economy.