Can we explain the gap between S&P and Euro Stoxx equity risk premia in the recent period?

In the recent period , the equity risk premium has become much lower for the S&P than for the Euro Stoxx . This means that the US equity market has risen relative to the euro - zone market more than what the changes in earnings per share should imply . This gap between the equity risk premia for the Euro Stoxx and the S&P is probably explained by the current or expected supply-demand equilibrium : Net share buybacks in the United States, which are likely to increase due to the repatriation of earnings from abroad , which is not happening in the euro zone; Purchases of US equities by non-residents and , recently, sales of euro - zone equities by non-resident s .