Indeed it would be nice to see a more definite and representative source for income. I wonder, since the process is more complicated, you should now include both the line engineers and also the people working near minimum wage to make the parts for these cars. Did Ford make most of its own parts? How much was off the shelf, and were there industries that existed solely to make parts for these cars?

> For one, far fewer households today are single salary. Say what you will about whether this is a good or bad thing, but I think it's probably more appropriate to base the numbers on an "automotive household income" if that's such a thing.

How many households had two Model Ts, and how many households today have two cars?