1) There are a number of factors that cause economic progress. Name and explain how four of these factors, discussed in this course, cause economic progress. What is the most important factor in causing economic progress that has been discussed in this course? Why is it the most important factor? Read chapters 6 (pp. 177-179) and 9 (pp. 241-264) in Krugman and pp. 63-67 and 634-639 in Reisman's book before answering this question. (No more than two pages)