Historian: During the Industrial Revolution, for the first time in history, the productivity of the economy grew at a faster rate than the population and thus dramatically improved living standards. An economist theorizes that this growth was made possible by the spread of values such as hard work and thrift. But successful explanations need to be based on facts, so no one should accept this explanation until historical evidence demonstrates that a change in values occurred prior to the Industrial Revolution. The overall conclusion of the historian's argument is that ["no one should accept the economist's explanation until historical evidence demonstrates that a change in values occurred prior to the Industrial Revolution", 'during the Industrial Revolution the productivity of the economy grew at a faster rate than the population', 'the improvement in living standards that occurred during the Industrial Revolution was not due to the spread of a change in values', 'values such as hard work and thrift did not become widespread prior to the Industrial Revolution']