Anchor: Because of difficulties in measuring productivity of farms and nonmarket activities, the most widely used measure of labor productivity growth is the rate of increase in nonfarm business sector output per hour worked.
Entailed: Due to difficulties in measuring productivity, labor productivity growth is a use rate of measure.
Contradiction: There are no difficulties in measuring productivity of farms.
Contradiction: He said they were unable to see how he really is. 
Contradiction: I came back and still didn't realize why I was depressed all winter.
Contradiction: They just decreased minimum wage today.
Contradiction: Children are having fun.