Contrary to widespread belief, voting machines of older types, such as lever and punchcard systems, are not used in counties with lower income - and newer machines, such as optical scanners and electronic machines, are not used in richer counties. We provide an economic explanation for this and...

What obstacles prevent the most productive technologies from spreading to less developed economies from the world's technological frontier? In this paper, we seek to shed light on this question by quantifying the geographic and human barriers to the transmission of technologies. We argue that...

What obstacles prevent the most productive technologies from spreading to less developed economies from the world's technological frontier? In this paper, we seek to shed light on this question by quantifying the geographic and human barriers to the transmission of technologies. We argue that...