In recent years, the federal government (under Republican and Democratic administrations alike) has encouraged the outsourcing of core parts of public education's work, including testing and test preparation, teaching and tutoring, data collection, and human resources management. However, researchers have found little evidence to support policy makers' assumption that privatization will lead schools to become more efficient and effective. If anything, evidence suggests that market-friendly education reforms have had negative effects on teaching and learning, especially for children from disadvantaged backgrounds.