For most people, tax is something we pay, simply because we must. We seldom think much more about it, in fact, tax is something we'd rather forget. But the reality is that tax is the key to power. No government can survive without tax revenue—it is the fuel that every state, large and small, runs on. Many of the problems we face today, not least the enormous wealth gaps between rich and poor and between generations, can be traced back to our systems of tax. If you tax windows, many will sacrifice their daylight. If you tax cigarettes, some people will choose not to smoke, others will take up smuggling. Tax companies too much and many will relocate off-shore.