<P> For example, should the companies providing the technology platform be liable for the actions of the suppliers in their network? If consumers tend to be higher income persons while the suppliers are lower - income persons, will the lower cost of the services (and therefore lower compensation of the suppliers) worsen income inequality? These are among the many questions the on - demand economy presents . </P> <P> Economist Paul Krugman summarized his views of the literature on the economic impact of immigrants on the U.S. economy as follows in March 2006: </P> <Ul> <Li> Net benefits to the U.S. economy from immigration are small overall, with an estimated less than 1% added to the total income of native - born Americans, even though the immigrants may benefit significantly . </Li> <Li> Poorer native - born Americans are hurt by immigration, particularly from Mexico . The additional supply of lower - educated immigrants from Mexico may have subtracted up to 8% from the wages of native - born American high school dropouts . </Li> <Li> Lower income immigrants place additional strain on the social safety net, particularly in certain states . </Li> <Li> Immigrants have a limited impact on income inequality . </Li> </Ul> <Li> Net benefits to the U.S. economy from immigration are small overall, with an estimated less than 1% added to the total income of native - born Americans, even though the immigrants may benefit significantly . </Li>

List three reasons for the disappearance of unemployment in the united states