Suppose there are two rich families. In one family, the head of the family dies in a car accident, and the rest of the family pays inheritance tax. The family in which a death occurred pays more tax than the family without deaths. I do not think this is fair. This is taxing misfortune. We do not collect extra taxes from people who lost their jobs or from people whose houses were destroyed.
The family with no deaths will probably pay inheritance tax in the future. A delay in paying taxes is equivalent to getting a low interest loan from the government.
Suppose there are two rich families. In the first family, people have children at age twenty. The family will pay inheritance tax about once every twenty years. In the second family, people have children at age forty. The family will pay inheritance tax about once every forty years. Over long periods of time, the second family will pay half as much inheritance tax as the first family. Is this fair?
Another problem with the inheritance tax is that marriages are exempt. So people can avoid inheritance tax by marrying their heirs, or by marrying someone who will marry the heir after death. This may become a bigger problem in the future if homosexuals succeed in eliminating laws about who may marry whom.
Another problem with the inheritance tax is that the amount of inheritance tax collected by the government is unpredictable, which disrupts government budget planning.
It would be better if rich people pay a little tax every year instead of paying a lot the year they die and no tax in other years.
The problems with the inheritance tax can be avoided by replacing the inheritance tax with a wealth tax. I think the rate should be one and one half percent per year, of wealth in excess of ten million dollars per person.
If inflation is three percent and the income tax rate is thirty three percent, then this is equivalent to a wealth tax of one percent. A poorer person in the ten percent income tax bracket would pay a wealth tax of one third of one percent. So inflation as a wealth tax is graduated like the income tax.
The advantage of the inflation tax is that it is easy. Taxpayers do not need to fill out any forms, and the government does not need to process any tax forms. But I think it would be better if the government did not create inflation, and collected taxes explicitly.