The day-to-day living conditions of modern Americans are very different from what they were in the 20th century. While doing research for an economics project, Charlie discovers that more households today, as compared to households 100 years ago, have electricity, air conditioning, and a car.
Which of the following explains why modern Americans enjoy a higher standard of living than Americans 100 years ago? (1)
which field do researchers focus on investigating the phenomena described?(2)