  Two decades of studies have found significant regional differences in the
timing of transitions in national business cycles and their durations. Earlier
studies partly detect regional synchronization during business cycle expansions
and contractions in Europe, the United States, and Japan. We examine this
possibility applying a sophisticated method for identifying the time-varying
degree of synchronization to regional business cycle data in the U.S. and
Japan. The method is prominent in nonlinear sciences but has been infrequently
applied in business cycle studies.We find that synchronization in regional
business cycles increased during contractions and decreased during expansions
throughout the period under study.Such asymmetry between the contraction and
expansion phases of a business cycle will contribute our better understanding
of the phenomenon of business cycles.
