How do I get out of the “revealed preference” dilemma with the Doukhobor and alcholics? I’m not really sure. I suppose the best attempt I can make is that “preference” matters, rather that “revealed preference”. So doing something that goes against the preferences of your “true rational self” – because of a compulsion or mania – would be irrational.

Hence, when incomes go up, people choose to have fewer children, because children are, strictly speaking, a poor investment. The “value” that parents place on kids—I’d give up my house before my kid, I’d give up my life before that of my kid—isn’t an economic calculation. It’s love.

Or is there some rational economic explanation for love, too, that I’m unaware of?

The bottom line is that while economic considerations play a role, so do lots of other things and it is just silly to pretend that economics is what really drives all of it.

What’s the alternative to “revealed preference”?

If someone has kids (deliberately), hates it and would rather have got a new pair of golf clubs, I’m guessing that’s irrational due to insufficient information. If someone decides they want kids, tries very hard to have kids, has them, loves it, and wouldn’t change it for the world, I’m guessing that’s rational. Other than to to ask their opinion? (And I’m guessing an alcoholics expressed opinion would be that alcholism is not their choice).

Are alcoholics rational? Their revealed preference is to blow all their money on booze and die young.

In the vast majority of cases, childraising reduces your net worth, often greatly. How do economists treat other behavior patterns which lead to a reduction of net worth?

Is childraising a recreational activity, comparable to raising expensive pets.

If potential parents realized the problem and quit having children, as happens in some places, is that a good thing?

If you are involved in policymaking you use the implicit model if the explicit model leaves important factors out. I don’t see the problem with this. It sounds like ass-covering—“Sure, I was wrong, but I was using a scientific model”.

When your spouse or partner first caught your eye was it visions of twenty dollar bills that danced through your head?

One of the things that makes people good analysts is knowing the limitations of their models. I know quite a few economists who suffer from deficiencies in this department but there is no reason for us all to follow them into pixie land.

But is having children really “economically irrational”? Empirically, you can make the case that people do seem to place a very high value on them. If you ask people whether they’d rather lose their house or their child, they’ll probably say their house. So the child has to be worth more. And that’s even when children are quite old – and have depreciated in terms of the utility you get from playing with them when they’re small.

You could phrase it another way, why is giving children up for adoption unusual? People have a clear choice: keep them or give them away. Presumably the reason people choose to keep them is that knowing their child is worth more that the loss of time and income that the other choice brings. I know there are sunk costs in terms of the pregnancy, but even if you offered to compensate people for this (i.e. I’ll buy your first born son for $100,000), I’ve a feeling most of them would say no.

I think by “economically rational” there’s an assumption this just means maximise the amount of cash you earn. I’m not sure that’s the case.

pleeeeeassse, “fewer”.

The OED finds contrary citations from King Alfred (Swa mid laes worda swa mid ma) to Caxton (Be cause he had so grete plente of men of hys owne countre, he called the fewer and lasse to counseyll) to Lyly (I thinke there are few Vniuersities that haue lesse faultes than Oxford) and on down the centuries to recent numbers of Nature. It’s very elegant, but like most pop-grammarian pedantry the alleged “fewer”/”less” distinction is a mare’s nest, unsupported by the language’s actual history.

Native speakers only: please fill in the blanks.

Write “Grammar is a descriptive science” on the blackboard 100 times, and not one time _.
Complete this sentence in 25 words or _.
My dictionary cost sixty quid, much _ than I expected.
The baby is _ than six months old.
America has _ than 200,000 troops in Iraq.
Our building is eight stories high, one _ than the campus average.
Yesterday I left a fifty-cent tip; today I’m leaving five cents _.
Six is one _ than seven.

Truth to tell, nowadays, a great deal of her wealth is due to the original choice to buy a house in coastal California, for which most of the credit is due my late father, who made the mortgage payments for thirty years and died in timely fashion.

It’s not a bad rule of thumb, john emerson, to assume that any economist well-known for his or her public dogmatism ain’t much of an economist. There are exceptions – Krugman, Friedman, etc – but they’re just that, exceptions. Economists attached to financial institutions and business lobby groups should be certainly be ignored in public debate.

But if you actually have some policy responsibility, then you have to recommend something – absent a better model you use the one you know, warts and all. For absent an explicit model you’ll be using an unacknowledged implicit model, whose assumptions and logic are therefore untested.

That is exactly what happens when income rises and/or reproductive choice becomes more available.

The proportion of part-time jobs is, I think, higher in Australia than in the US and their relative pay and status is also higher than in the US (though not as good as might be hoped).