This is a very big question.
As one of the other witnesses said, it probably goes back to the early 1990s. Many things have happened in the world to cause inequality in OECD countries, including more competitiveness for manufacturing industries. We've seen a decline in manufacturing industries and the middle-income jobs that go with the industries. We've seen a competing down of redistributive policies because of mobility of capital and highly skilled people across countries.
I think it's hard to pinpoint exactly what the cause of it is. My concern is really more that we haven't responded as well as we could have. At the same time as inequality has increased, our policies have become less and less effective at dealing with it.