TOEFL iBT Speaking. In this integrated speaking task, you will listen to part of

Listen to part of a lecture in an economics class.
Sometimes unemployment occurs when workers are simply moving between jobs. Sometimes it occurs when the economy suffers a downturn and large numbers of workers are laid off. How do we know how many people are unemployed? We mainly know through statistics on the labor force, which the government collects every month in a procedure known as random sampling of the population. Random sampling consists of choosing a part of the population at random and then surveying the selected group. Each month, researchers interview 60,000 households and ask questions about their recent work patterns.
The government divides the population—that is, men and women age 16 years and older—and puts them into three groups: employed, unemployed, and outside the labor force. The employed are people with jobs and people who performed any paid work, and also people with jobs but absent from work because of illness, vacations, or strikes. The unemployed are the people without jobs but who are actively looking for work or waiting to return to work after a layoff. People outside the labor force are those who don’t have jobs but are not looking for
work. They might be going to school, caring for children, retired, or too sick to work. This last group also includes people without jobs who have stopped looking for work.
The total labor force consists of the first two groups, the employed and the unemployed—people with jobs and people looking for jobs. The government calculates the unemployment rate by taking the number of unemployed and dividing it by the total labor force. So the unemployment rate is the percentage of people who are out of work but looking for work.
Using points and examples from the lecture, explain how the government studies the labor force and unemployment.