When is it preferable to use a currency hedged ETF over a none currency hedged ETF? There has been studies which have shown over the longer term currency hedging does not make a difference.

"However, we believe that studies and our own experience have generally shown that over long measurement periods, the returns of hedged portfolios have been similar to the returns of portfolios that have not been hedged."

• TWEEDY, BROWNE FUND INC

However there is clear evidence this is not the case over the short term. Take Japan for example, the two largest ETFs EWJ in red and the currency hedged DXJ in blue. . There are clear periods where one variant is more a preferable investment over the other.

Using interest rates, currency rates and some other metrics how can you decide to use a currency hedged ETF or not?

When is it preferable to use a currency hedged ETF over a none currency hedged ETF? There has been studies which have shown over the longer term currency hedging does not make a difference.

"However, we believe that studies and our own experience have generally shown that over long measurement periods, the returns of hedged portfolios have been similar to the returns of portfolios that have not been hedged."

• TWEEDY, BROWNE FUND INC

However there is clear evidence this is not the case over the short term. Take Japan for example, the two largest ETFs EWJ in red and the currency hedged DXJ in blue. . There are clear periods where one variant is more a preferable investment over the other.

Using interest rates, currency rates and some other metrics how can you decide to use a currency hedged ETF or not? Can the same approach be applied to regional ETFs (EEM, EFA exc.)?