The link between poverty and poor educational attainment is a strong one. In 'developed' nations, it has become a truism that students from deprived inner-city areas are, on average, likely to achieve lower grades than those from the affluent suburbs. For decades, the causes have been identified, debated and tackled. Educational policies designed to tackle the problem have been developed, altered, dropped and replaced. But the problem remains. It's a big, complicated issue and no-one seems to have the answer.