The historic swearing-in of Michelle O’Neill as first minister of the Northern Irish Executive marks the first time that Sinn Féin has led a government on this island since 1922. While the party’s fortunes have dwindled somewhat according to recent polls in the Republic, it remains a formidable force with good prospects to take power in Dublin after the next general election. If this came to pass, what would Sinn Féin’s economic policy be?  Many aspects of the party’s programme remain opaque. Like all political parties, it knows that pinning its colours to the mast too early can hurt its…