A 1987 Time Magazine report found that roughly 160 countries around the world had governing documents modeled at least in some part after the U.S. Constitution. However, as of 2012, many countries had amended their charters in ways that made them more dissimilar than at any point since the 1940s.
A study by law professors from Washington University in St. Louis and the University of Virginia found that in the 1960s and 1970s, the constitutional provisions adopted in the 188 countries studied brought their governing documents closer in content to the U.S. Constitution. However, that trend declined in the 1980s only to completely reverse itself on into the 20th century. Some have attributed this change in large part to the fact that the government changes the U.S. Constitution far less often than other countries alter their charters, rendering the U.S. Constitution out of date with the needs and desires of countries drafting documents in modern times.