If a person enjoys the benefits of a group's collective efforts but does not contribute to those efforts, he or she is called a

The answer is free rider. A free rider is a person who benefits from something without applying any efforts or paying for it. In other words, Free riders uses the utility without paying their fair/equal share/part. They consume benefits of a public good without contributing from their side. Examples could include: Lighthouse, fish stock preservers.

World War II began in Europe on September 1, 1939, when Germany invaded Poland. Great Britain and France responded by declaring war on Germany on September 3. The war between the U.S.S.R. and Germany began on June 22, 1941, with the German invasion of the Soviet Union.