Connectionist-Based Rules Describing the Pass-Through of Individual Goods Prices into Trend Inflation in the United States

Abstract

This paper examines the inflation pass-through problem in American monetary policy, defined as the relationship between changes in the growth rates of individual goods and the subsequent economy-wide rate of growth of consumer prices. Granger causality tests robust to structural breaks are used to establish initial relationships. Then, feedforward artificial neural network (ANN) is used to approximate the functional relationship between selected component subindexes and the headline CPI. Moving beyond the ANN black box, we illustrate how decision rules can be extracted from the network. Our custom decompositional extraction algorithm generates rules in human-readable and machine-executable form (Matlab code). Our procedure provides an additional route, beyond direct Bayesian estimation, for empirical econometric relationships to be embedded in DSGE models. A topic for further research is embedding decision rules within such models.