This paper deals with simultaneous interactions between the determinants of the US yield curve. For this purpose, we derive a multivariate unobserved components model based on the expectation hypothesis. The influencing factors of the term structure that arise from the structural model are a common stochastic trend, the cyclical part of the short rate and maturity-dependent term premiums in the longer rates. We establish a significant influence of both permanent and transitory innovations on the US term structure and find pronounced spillovers between the shocks of the term structure determinants. An interesting result depicts a key role of the spillovers of structural mid-term rate cycle shocks in the formation of the risk premiums.