It deals with opportunity costs. Opportunity costs are not real costs, but rather the things that you had to give up in order to obtain something else. What you didn't obtain is considered to be an opportunity cost. A production possibility curve deals with this.
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From 1942 to 1947, only a relatively small number of braceros were admitted, accounting for less than 10 percent of U.S hired workers. Yet both U.S and Mexican employers became heavily dependent on braceros for willing workers; bribery was a common way to get a contract during this time. Consequently, several years of short-term agreement led to an increase in undocumented immigration and a growing preference for operating outside of the parameters set by the program. Moreover, Truman's Commission on Migratory Labor in 1951 disclosed that the presence of Mexican workers depressed the income of American farmers, even as the U.S Department of State urged a new bracero program to counter the popularity of communism in Mexico. Furthermore, it was seen as a way for Mexico to be involved in the Allied armed forces. The first braceros were admitted on September 27, 1942, for the sugar-beet harvest season. From 1948 to 1964, the US imported on average 200,000 braceros per year.
During the changes of state known as D. vaporization and sublimation do the atoms overcome the attractive forces between them.
