Ask HN: How Many Other Jobs Result from One Software Engineer?

In the early nineties my friend Efren Ibarreta told me that each software engineer resulted in twelve people having other kinds of work - managers, QA, sales and so on. However I don't know where he got that figure, nor do I know what the ration is currently, or whether anyone is even tracking it.

My personal experience at the time jived with the twelve to one ratio but these days I am not so sure. Consider that it is uncommon for anyone to pack and ship physical products, or to have a live human to answer telephones to take orders.

I'm not able to find a link, although I'm not real sure what a good search query would be.