The changing relationships between the G-7 countries are examined through VAR models for quarterly growth, estimated over sub-periods and using a rolling data window. Trivariate models are employed, each including the US and a European (E15) aggregate. The results show that conditional volatility of growth has declined relatively more since 1980 for E15 than for the US, aggregate European shocks have increased impact on “core†European countries from around 1980, the effects of the US on Europe are largest during the 1970s and the late 1990s, and E15 has a steadily increasing impact on the US economy over time. Copyright Springer Science + Business Media, LLC 2006european integration, international business cycle, time variation and volatility,