 These "underclass" jobs, which have a disproportionate number of undocumented immigrants, include harvesting crops, unskilled labor in landscaping and construction, house-cleaning, and maid and busboy work in hotels and restaurants.However, as even these "underclass" jobs have higher relative wages than those in home countries they are still attractive for undocumented immigrants and since many undocumented immigrants often anticipate working only temporarily in the destination country, the lack of opportunity for advancement is seen by many as less of a problem.Support for this claim can be seen in a Pew Hispanic Center poll of over 3,000 undocumented immigrants from Mexico in the US, which found that 79% would voluntarily join a temporary worker program that allowed them to work legally for several years but then required them to leave.