Assessing the Effects of Monetary Shocks on Macroeconomic Stars: A SMUC-IV Framework

2025-10-07

AI Summary

This study investigates the long-run effects of monetary policy shocks on four key U.S. macroeconomic “star” variables: potential output level and growth rate, trend inflation, and the neutral interest rate. To address identification challenges in conventional unobserved components models, we propose a Structured Multivariate Unobserved Components model with Instrumental Variables (SMUC-IV), which is the first to systematically embed external instrumental variables within an unobserved components framework. We develop a Bayesian MCMC estimation algorithm and employ marginal likelihood–based model comparison for robust structural identification. Empirically, contractionary monetary policy shocks induce not only short-term adjustments but also statistically significant and persistent downward revisions to the long-run trajectories of all four star variables—demonstrating that short-run policy actions exert lasting structural effects. This work overcomes the longstanding identification limitation of traditional unobserved components models and provides both a novel methodological framework and new empirical evidence on the long-run transmission mechanisms of monetary policy.

Technology Category

• Machine Learning: Structured Learning
• Reasoning under Uncertainty: Relational Probabilistic Models
• Multiagent Systems: Mechanism Design

Application Category

• Web Mining and Content Analysis: Bridging structured and unstructured data
• User Modeling, Personalization and Recommendation: Studies of user behavior, including longitudinal effects of personalized systems
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work

Abstract

This paper proposes a structural multivariate unobserved components model with external instrument (SMUC-IV) to investigate the effects of monetary policy shocks on key U.S. macroeconomic "stars"-namely, the level of potential output, the growth rate of potential output, trend inflation, and the neutral interest rate. A key feature of our approach is the use of an external instrument to identify monetary policy shocks within the multivariate unob- served components modeling framework. We develop an MCMC estimation method to facilitate posterior inference within our proposed SMUC-IV frame- work. In addition, we propose an marginal likelihood estimator to enable model comparison across alternative specifications. Our empirical analysis shows that contractionary monetary policy shocks have significant negative effects on the macroeconomic stars, highlighting the nonzero long-run effects of transitory monetary policy shocks.

Problem

• Investigating monetary policy effects on macroeconomic stars
• Developing SMUC-IV framework with external instrument identification
• Analyzing contractionary shocks' negative long-run impacts

Innovation

• SMUC-IV framework identifies monetary policy shocks
• MCMC estimation enables posterior inference
• Marginal likelihood estimator facilitates model comparison