Why did Asians migrate to Oceania and America before19th century?

/kloc-population migration before the 0/9th century In the late ancient times and early Middle Ages, a large number of population migration had a great influence on the origin of many ethnic groups in Europe and Asia. After the great discovery of geography, the climax of population migration was set off in 15 ~ 16 century. A large number of immigrants moved from Europe to the United States: at first there were Spanish and Portuguese, and later there were French, Dutch and British. Only in the second half of the 1 8th century, nearly110,000 people moved out of Europe; Colonists also transported millions of black people (including tens of millions of dead people) from Africa to America, which led to a significant decline in the absolute population of Africa in the18th century. In the19th century and the early 20th century, they mainly immigrated from Europe to America. From the beginning of the 20th century to 19 14, more than 50 million people moved out of Europe, and a large number of immigrants mainly moved to the United States, as well as Canada, Argentina, Brazil, Australia, New Zealand and other places. Population migration in Asia, Africa and Latin China is relatively small, with some people migrating to Southeast Asian countries, Japanese people migrating to Hawaiian Islands, the United States, Brazil and North Korea, and Indians migrating to Ceylon (now Sri Lanka), Myanmar, Malaya (now West Malaysia), Mauritius and Fiji Island in Oceania. There are hundreds of people. Population migration from World War I to World War II. World War I caused massive population migration in Europe. For example, 500 thousand people in Germany returned from Poland; Nearly half a million people returned to Hungary from Czechoslovakia, Romania and Yugoslavia. During the Soviet civil war, nearly 2 million people moved out of Russia, and so on. After the end of World War I, European immigrants became active again. At the beginning of the 20th century, the emigration of European countries to overseas countries reached its peak (with an average of 600,000 people moving out every year), and then declined, because the economic crisis in the United States, Canada, Australia and other countries increased the number of unemployed people and restricted immigration. At this time, Italians and Spaniards in southern Europe mainly migrated to Latin America (Brazil and Argentina). In the mid-1930s, European immigrants to overseas countries increased again, mainly from fascist countries and their occupying countries. From 19 18 to 1939, there are nearly 9 million European immigrants. About half of them moved to the United States, and nearly 300,000 Jews moved to Palestine from European countries (mainly Germany). Population Migration After World War II, millions of peaceful residents fled and retreated from the military operation zone, resulting in a new large-scale population migration. More than 40 years after the war, international migration has become more complicated, which is characterized by: (1) political international migration is larger, more complicated and lasts longer than before the war. The main reasons are: ① the repatriation of soldiers and civilians in occupied areas or occupied areas after the war; ② The adjustment of borders between countries after the war caused the population migration of residents and some ethnic groups; (3) The establishment of some new countries, or the partition of a country, caused a large number of population migration; (4) The independence of some countries in Asia, Africa and Latin America has led to the international migration of some people. (2) The scale of international migration of foreign workers is obviously larger than that before the war. At the peak, there were 30-40 million foreign workers, mainly distributed in North America, Western Europe, the Middle East, South America, South Africa and Australia. The reasons are as follows: (1) The two world wars destroyed the economies of some countries in Western Europe, resulting in an increase in mortality and a decrease in birth rate. In the climax of post-war economic recovery and development, the labor force was insufficient; (2) In some underdeveloped countries, population growth is fast, economic growth is slow, unemployment is prominent, and wages are low, so there are often a large number of surplus labor forces in these countries; (3) In areas with rapid economic progress in recent years, such as oil-producing countries in the Middle East, mining areas in Australia and South Africa, the extraordinary economic development often leads to labor shortage; (4) In developed countries, the education level of workers has generally improved and their material living conditions have greatly improved. People don't want to do those heavy jobs. Therefore, in these countries, on the one hand, there is an army of unemployed people, on the other hand, there is a phenomenon that the so-called "blue-collar" can't find employment targets; ⑤ The pattern of population growth has changed greatly, from rapid population growth to low growth in the early days of capitalism. The problem of aging population in these countries is increasingly prominent, and the young and middle-aged labor force is increasingly scarce; ⑥ In developed capitalist countries, the agricultural population has dropped to below 10% or even 3-4%. The sources of labor such as industry, transportation and construction can no longer be supplemented by the agricultural population. As a result, a large number of labor force flows from underdeveloped countries to developed countries. (3) The flow of international immigrants has changed after the war. First, Europe, a traditional net immigrant area, has become a net immigrant area. However, the situation in European countries is different. /kloc-After the 1960s, northwest Europe was a net immigrant area, while southern Europe was almost a net immigrant area. In the 1950s, many Europeans still immigrated to North America and Latin America. Due to the rapid economic growth in Europe in the 1960s, many Europeans returned to their "hometown". Second, Latin America has changed from a traditional net immigrant to a net immigrant area. Third, the United States, Canada, Australia and New Zealand, which have traditionally accepted a large number of immigrants, have not changed much since the war. Immigrants from these countries mainly came from Europe in the early 1950s. In the late 1960s, Latin American immigrants surpassed European immigrants; Since 1970s, immigrants from Asia have surpassed those from Europe, many of whom are intellectuals. The international migration of population affects the supply and demand of labor in relevant countries, and then it will have a certain impact on the employment and wages of emigration and emigration countries. Therefore, the international migration of population is a highly policy-oriented work.