How much well or badly the melting copper of the country accepting immigrants works, most easier to judge on degree visitors in a local labour market. The organisation on cooperation and development (), uniting three ten developed countries, has attended to this theme some years ago when in Europe still blew up nothing and did not burn. Problem studying has occupied some time: the organisation has published first four cases only in March of it. «The first caused Germany, Sweden, Australia and Denmark», - economist, the author of three researches from four tells. On the way the cases devoted to Belgium and France.