A consensus has developed in political and also media circles that in Britain over recent decades social mobility has been in decline. According to the consensus view, as construed in political circles, educational policy is seen as the crucial instrument for increasing mobility. This article shows how the consensus emerged from the research of a group of economists into intergenerational income mobility. It is argued that, primarily on account of various limitations of the available data, the economists’ finding of declining mobility is open to question; and, further, that, because no explicit distinction is made in their work between absolute and relative rates of mobility, its reception, among politicians especially, has been attended by considerable confusion. An alternative to the consensus view is put forward, based on extensive research by sociologists into social class mobility, which is seen as better capturing the intergenerational transmission of economic advantage and disadvantage. This research indicates that the only recent change of note is that the rising rates of upward, absolute mobility of the middle decades of the last century have levelled out. Relative rates have remained more or less constant back to the inter-war years. According to this alternative view, what can be achieved through education, whether in regard to absolute or relative mobility, appears limited.