My guess? Money. Big cities are expensive (NYC has a ~3.5% city income tax). While incomes in rural areas are lower, the cost of living is lower too. And it d

My guess? Money. Big cities are expensive (NYC has a ~3.5% city income tax). While incomes in rural areas are lower, the cost of living is lower too. And it doesn't have to be a rural area - just a city or region with a lower financial impact on a household could be enough to induce them to leave a high-tax area.