Once more following in David Cameron's footsteps, Nick Clegg is delivering tonight's Hugo Young memorial lecture. A preview of his speech appears in today's Guardian, in which the Lib Dem leader suggests that increasing social mobility, not achieving income equality, should be the ultimate goal of progressives.
Social mobility is what characterises a fair society, rather than a particular level of income equality. Inequalities become injustices when they are fixed; passed on, generation to generation. That's when societies become closed, stratified and divided.
The problem with Clegg's argument is that the countries with the highest levels of social mobility are those with the lowest levels of inequality. As the graph below (from the excellent book The Spirit Level) shows, countries such as Sweden, Norway, Denmark and Canada, where income inequality is low, have far higher levels of social mobility than the United States and the UK, where income inequality is high. This is hardly surprising: greater inequalities of outcome make it easier for rich parents to pass on their advantages to their children. Clegg's suggestion that progressives must prioritise either social mobility or income inequality is empirically unsound.
The data on equality and social mobility also undermines his argument against the 50p tax rate. He attempts to characterise Ed Miliband as an "old progressive" due to his support for a permanent 50p rate. But it is no coincidence that the most equal countries in the world are also those with the highest rates of income tax. Japan, the most equal country in the world, has had a top rate of 50 per cent for many years, Sweden, the second most equal country in the world, has a top rate of 56.6 per cent. The correlation continues: Denmark has a top rate of 55.4 per cent, Norway a top rate of 47.8 per cent and Finland a top rate of 49.6 per cent.
Clegg's refusal to acknowledge all of the above reveals either his ignorance or his disingenuity. Until he accepts that the most socially mobile societies are also the most equal, no one should take his "progressive" claims seriously.