This paper examines travel visa restrictions in 188 countries. We measure travel visa requirements (1) facing foreign visitors into a given country and (2) facing citizens of a given nation traveling abroad. Our analysis shows that countries are more likely to impose visas on foreign visitors...

Alchian and Allen (<CitationRef CitationID="CR1">1964</CitationRef>) theorized that the imposition of a fixed fee or a unit cost in a market with multiple quality grades of the good would encourage consumption of the higher quality grades. Using newly available data on marijuana prices by state, we empirically test the hypothesis that the...</citationref>

This article uses K-means clustering to group countries using the information from the five areas of the Economic Freedom of the World (EFW) index. The resulting clusters of countries are similar but not identical to quartile groupings found using the overall EFW index. Simple comparisons of...