text: labour migration tends to be passive, 6ince they are generally unable to initlate or to deternine the pace of labour roigration flons. In addition, labour emigratlon does not necessarily leatl to a reduction of unemployroent' partty because the skillsA/ 40 /5L9 Enqli sh Page 106 of those who leave are not always easy to replace. fn fact, there is evldencesuggesting that some sending countr,ies have actually become labou r -i mportingcountries in order to reprace the needed skirrs rdhich have been rost thioughemigration. !f/ Thus, labour emigration affects not only the size of labour supplybut a1so, and most importantly, its composition and may have undesirableconsequences even when reducing national levels of supply. 236' Another aspect of international rabour nigration that may have detrimentaleffects for sending countries is the return of migrants, especially when rt occurson a large scale as part of the discontinuation of a rrell establisheal flow.Mlgrants returning in such ',unplanned,' circumstances are often i11 prepared tostart anew in their country of origin and the nationar economy is unrikery to beready for the absorption of a sudden increase of labour suppty. However, not allreturn migration occurs under such circumstances. The orderry return of migrantsassociated with the enforcement of labour rotation by the recelvrng states may beaccompanied by minimum disruptions and may even reaal to overall benefits if chesavings accumulated by migrants while abroad are put to productive use.
analysis: The text primarily discusses the effects of labour migration on sending countries, including the potential consequences of returning migrants, the replacement of skills, and the impact on national labour supply and composition. The text does not explicitly mention economic development, natural resources, or environmental issues. It also does not discuss industry, transport, communication, humanitarian aid, culture, or science and technology. The topics of employment, education, and international trade are related, but the text focuses more on the labour migration aspect rather than the broader economic context.