Professor Friedman, do you accept the common perception that GDP is a measurement of actual economic growth? Or, would you agree with the folks at Redefining Progress that GDP tells us nothing about the state of well-being of people, generally. Their measure, the Genuine Progress Indicator, suggests that we have been in decline as measured by well-being since the late 1970s. You also allude the the fact that per capita income or output say nothing about whether income or wealth distribution is just (i.e., that producers retain that portion of total goods produced or service values provided with which they were responsible. As for technological progress, your students might benefit by taking a look at the series of documentary films written by James Burke ("The Trigger Effect" and "The Day the Universe Changed").