Samuelson Samuelson Samuelson was born in Gary, Indiana, USA on May 19 15. At the age of 20, he graduated from the University of Chicago with GPA and got a bachelor's degree in literature. In the second year, he got a master's degree from Harvard University. Five years later, he received a doctorate from Harvard University. In addition, Samuelson also received honorary degrees from several universities. His doctoral thesis, entitled "The Operational Significance of Economic Theory", won the David A. Wells Award from Harvard University. At the annual meeting of American economics from 65438 to 0947, Paul Douglas, as the president of the society, awarded the first john bates clark medal to Samuelson, who was less than 40 years old at that time, and predicted that Samuelson had a bright future in the field of economics. Sure enough, Samuelson lived up to expectations. Twenty-three years later, he won the highest prize in world economics-the Nobel Prize in Economics. Since 1940, Samuelson has also served as the president of American Econometrics Association, American Economic Association, international economics and honorary president for life, and served as economic consultant and researcher in a series of government agencies and companies. Samuelson's works are rich. His main works are: Fundamentals of Economic Analysis (1947). ), Economics (1948. ), Liner programming and analysis (1948. 1958), as well as a large number of articles written alone and co-authored with Dofman and Thoreau, were selected into the first, second, third, fourth and fifth episodes of Paul A Samuelson's Scientific Essays. Samuelson is ubiquitous in the field of economics and is called the last generalist of economics. People knew Samuelson as soon as they entered the university to study economics. They read Samuelson's textbook Economics. When entering the research of high-level economic theory, people still cannot leave Samuelson. At this time, Samuelson's "Basis of Economic Analysis" became a guide to economic theory research; In almost all fields of economics, such as microeconomics, macroeconomics, international economics and mathematical economics, people can always get inspiration and reference from Samuelson's related works. As a comprehensive representative of neoclassical economics and Keynesian economics, Samuelson's theoretical viewpoints reflect the orthodox theoretical viewpoints of a whole generation of western economics and become the theoretical basis for western governments to formulate economic policies. In the 1970s, the economies of western countries fell into a stagflation predicament, which destroyed the economic policies based on "neoclassical synthesis". Samuelson's economic theory was challenged from all sides, thus forming a protracted debate in western economics. Although the orthodox position of Samuelson's economic theory has been shaken, the economy of western countries as a "mixed economy" is still inseparable from Samuelson's economic theory. Samuelson also absorbed many important theoretical viewpoints from the economic theories of other schools, and revised and improved his own theory to adapt it to the changed economic situation. From this perspective, Samuelson is also a master of economics. Samuelson's research scope spans many fields such as economics, statistics and mathematics, and he has unique views on the three major components of economics-political economics, departmental economics and technical economics. He combined Keynesianism with traditional microeconomics and formed the theoretical system of "Neoclassical Comprehensive School". He has always been keen on applying mathematical tools to the analysis of static equilibrium and dynamic process, studying economy by means of physics and mathematical reasoning, and making contributions to the modernization of mathematical economics. In addition, through the analysis of the interaction between multiplier and acceleration, he skillfully combined them into one, revealing the internal relationship between multiplier and acceleration; In the discussion of economic growth theory, the discussion of "social welfare function" in comparative cost theory and the supplement to "Heckschel-Olin principle" have all contributed valuable ideas to economic theory. Samuelson's theory maintained and spread the traditional western economic theory, promoted the development of pure mathematical economy and became a prestigious economic giant in the western world. Therefore, his works are republished in one edition and enjoy a high reputation all over the world. Samuelson's works mainly include: Fundamentals of Economic Analysis (1947), Economics (1948, published in 18) and Linear Planning and Economic Analysis (co-authored with Dorfman Solo, 1958). (1) Stolper-Samuelson theorem: the income of production factors is the income of production factors, and the income of factors is equal to the marginal product value of factors. The marginal product of factors is also the marginal productivity of factors. In the short term, although product prices will change due to international trade, it is too late for factors of production to flow between departments. Therefore, international trade only affects product prices in the short term. From the previous analysis, we know that the relative price of a country's export products will rise and the relative price of imported products will fall. Because MPL and MPK remain unchanged (because the factors of production do not flow), while the price of export products (PX) rises, the remuneration (WX, RX) of labor and capital used by export industries will increase. On the other hand, due to the decline in the price (PM) of imported products, the reward (WM, RM) of labor and capital used by imported competitive industries will decrease. In other words, the owners of production factors in export industries benefit, while those in import competitive industries suffer. In the long run, factors of production can flow freely between industries. The influence of international trade on the return of production factors should be analyzed in combination with the changes of product prices and marginal productivity of factors. As a result of trade, the capital and labor in the export industry will benefit and the remuneration will increase, so the capital and labor imported from competitive industries will flow to the export industry. Here we assume that the export industry is labor-intensive and the import competition industry is capital-intensive. In this way, the capital-labor ratio of imported competitive industries is high, and when the output of domestic imported competitive products decreases due to international trade, more capital is transferred than labor; On the other hand, labor-intensive export industries have higher labor and capital, and the demand for labor is greater than the demand for capital after the output of export products is expanded. In this way, more capital is transferred from imported competitive industries, but the demand is less; Less labor is transferred, but there is more demand. The result is a relative surplus of capital and a relative shortage of labor. If both industries produce according to the original capital-labor ratio, some capital will be idle. But when the capital is surplus, it will become relatively cheap, so the idle capital will be absorbed by the two industries to replace the relatively scarce and expensive labor (here we assume that labor and capital can replace each other). In this way, both industries will invest more capital to replace labor than before trade, so their capital-labor ratio will be higher than before trade. Due to the increase of capital investment, the marginal productivity of labor in various industries increases, while the marginal productivity of capital decreases due to the increase of capital investment. As a result, for the export industry, with the increase of PX, MPL also increases, so WX also increases, that is, the reward of intensive use of production factors in the export industry increases; For imported industries, with the decrease of PM, MPK also decreases, so RM also decreases, that is, the remuneration of production factors intensively used in imported competitive industries decreases. In the above long-term analysis, the influence of international trade on the capital return of export industry and the labor return of import industry is uncertain, but we can explain the changes of these two factors through the following deduction: our analysis has always assumed that the domestic factor markets of the first two countries are balanced, making the wage level of export industry equal to that of import industry, that is, RX = RM, and the profit level of export industry is also equivalent to that of import industry, that is, RX. After trade, the factor market will also be balanced, so the wages and profits of import and export industries will inevitably be equal in the new equilibrium state. In this way, after trade, we deduce that the wages of the export industry will rise and the profits of the import industry will fall. Then, in the case of WX = WM and RX = RM after trade, the wage level WM of the import industry will also rise, and the profit level RX of the export industry will also drop. Based on the above analysis, we can draw a conclusion: in the long run, after international trade, the remuneration of the factors of production intensively used in the production of export products (that is, the abundant domestic factors of production) will increase, while the remuneration of the factors of production intensively used in the production of imported products (that is, the scarce domestic factors of production) will decrease, no matter which industry these factors of production are used in. This conclusion was demonstrated by American economists Wolfgang Stolper and paul samuelson, so it is called "Stolper-Samuelson Theorem". From the above analysis, we can also see that after international trade, the change of factor reward will exceed the change of product price, because factor reward (price) is the product of product price and factor marginal productivity. This result is called the "amplification effect" of international trade. (II) Theorem of Factor Price Equalization As long as there are differences in product prices, the two countries will continue to trade, but the final result is that the prices of two products in the two countries are completely equal, and the prices of production factors are also completely equal. At this time, if other conditions remain unchanged, trade will stop. Due to the trade between the two countries, the trend that the prices of production factors between the two countries will eventually be equal is called the "factor price equality theorem". Because Samuelson demonstrated this theorem according to the logic of Heckel-Olin model, it is also called "Heckel-Olin-Samuelson Theorem".