However, Xavier Sala-i-Martin, a professor in economics at Columbia University, says that Mas is simply "following the crowd" on calls for sovereignty.

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Surprisingly, over the same period global inequality has fallen, from 0.66 in the mid-1980s to 0.61 in the mid-2000s, according to Xavier Sala-i-Martin, an economist at Columbia University.

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According to Columbia University economist Xavier Sala-i-Martin, the percentage of people in the world living on a dollar a day or less a traditional poverty measure has fallen by 80% since 1970.

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