I was pondering just now on road haulage. Lorry drivers are in the news a lot at the moment, and I was thinking about how lorries are quite a limited and old-fashioned approach to the problem of moving things around, as each of them can carry only a trifling proportion* of the freight that needs to be shifted (1,810,000,000 tonnes in 2006, just within the UK; if you were faced with a really big warehouse holding 1.8 billion tonnes of stuff and were asked to move it all, would you ever say "You know, I reckon about half a million trucks, each with its own driver, will be the best way to do that"?).
Anyway, given that we can best understand things if we quantify them, I thought I'd work out what proportion of all this freight each lorry moved on average. So using government figures I calculated:
effort = 100 * (amount of stuff moved / number of vehicles used to move it) / amount of stuff moved
which simplifies to:
effort = 100 * (1 / number of vehicles)
which told me that each lorry moves just 0.0002% of the freight. This presumably is why there is such a staggering number of them these days, either clogging motorways by overtaking one another at microscopic speed differentials, or clogging the A36 when I'm trying to get to work. Anyway, before I could do anything useful with this train of thought, I got distracted and realized we could generalize the approach like so:
effort = 100 * (1 / number of workers)
and started doing this with other professions where statistics on the amount of work and the number of workers are easily available. So here's what I've got so far, using the numbers of teachers, police officers, fishermen and GPs on the one hand and the numbers of school children taught, crimes committed, fish caught and people who might get sick on the other :
Teachers: each teaches 0.0001% of the children
Police officers: each investigates 0.0008% of the crimes**
Fishermen: each catches 0.0077% of the fish
GPs: each looks after 0.0029% of the people
Make of this what you will, but there does seem to be a case for paying teachers 8 times less than police officers, even before we factor in the relative danger :o). Oh, and well done you fishermen.
Any suggestions for other professions?
* Compared to, say, trains
** Or, alternatively, polices 0.0008% of the population if you prefer