Discounting and impatience with overlapping generations (Crossposted at CT)

During the discussion of discounting and the Stern Review, I got an email raising a point that I had already been worrying about. In discussing costs and benefits in 2100, I and others routinely refer to future generations, and in a sense that’s right, since the people involved in the discussion won’t be around then. But, children alive now have a reasonable chance of living to 2100 – quite a good chance if life expectancy keeps rising. Economists often deal with this kind of thing by modelling a series of overlapping generations, but I haven’t seen much discussion of this in relation to benefit-cost analysis, though no doubt it’s in the literature somewhere.

I finally got around to thinking about this, and in particular the following question. Suppose we accept an ethical framework in which everyone now alive matters equally. Suppose also that as individuals we have a consistently positive rate of time preference, preferring to have higher utility now at the expense of less in the future, that is, more when we are young and less when we are old (this isn’t obvious by the way, but I’m assuming it for the sake of argument) . What is the appropriate pure rate of time preference for society as a whole?

My preliminary answer, somewhat surprisingly to me, is “Zero”. I’ll set out the outline of the formal argument over the fold, but the simple summary has two parts. First, since generations overlap, if, at all times, we treat all people now alive as equal then we must treat all people now and in the future as equal. Given this equality, positive individual rates of time preference translate not into a social preference for the present over the future but into a social policy that consistently puts more weight on the welfare of people when they are young than when they are old.
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Weekend reflections

Weekend Reflections is on again. Please comment on any topic of interest (civilised discussion and no coarse language, please). Feel free to put in contributions more lengthy than for the Monday Message Board or standard comments.

Flexibility as a zero-sum game

If you want to see the new flexible workforce, go to Walmart (hat-tip Tim Dunlop). As Tim’s title suggests, there’s nothing new about workers being told, from day to day, whether they’ll be wanted and for how long – look at any old movie about the waterfront for illustrations. All that’s new is that it’s being done by computer now. And flexibility, in cases like this, is a zero-sum concept: the more flexibility our bosses have to direct us, the less we have to run our own lives.

Relative prices

Obviously, I’m not the only one who gets annoyed by pieces pointing to purchases of consumer goods as evidence that rising inequality isn’t really a problem. But, as an economist, it particularly annoys me when this claim is put forward by people who claim to understand markets. I’ve been going on about this for yearsand years.

The most important thing that happens in markets is that relative prices change. If prices change, but income and preferences don’t, what we expect is that people will consume more of the goods and services for which prices have fallen and less of those for which prices have risen. So, when Jeff Taylor tells us that

With price points dropping below the $1000 mark, high-end TVs are moving down-market fast with Wal-Mart leading the way.

we can all cheer this renewed verification of the Law of Demand. But, of course, this tells us precisely nothing about what’s happening to inequality.
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Time to go home

About the only thing that the supporters of the Iraq war have been able to claim as a success (at least with any plausibility) has been the removal of Saddam Hussein. Now that this removal has been made permanent, wouldn’t this be a good time to declare victory and pull out?
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Driving us digital

A recent government report spoke of driving Australians into the age of digital TV. Apparently, this kind of thing is what they have in mind.

Seriously, I wouldn’t object to auctioning off spectrum, even at some cost in terms of signal clarity, if new TV channels were allowed to bid. But the absolute rule of Australian media policy is to nothing contrary to the interests of the incumbent oligopoly.

Inconvenient Truth *Not* on YouTube

I finally got around to seeing An Inconvenient Truth on a plane flight* not long ago. It’s very impressive, and sticks pretty closely to the the science. Just after this, it was posted on YouTube in nine 10-minute segments, but by the time I got there it had been taken down again.

As I’ve mentioned before it’s striking how radically the debate changed in Australia over the course of 2006. Both the Gore movie and the Stern Review played a role in this, crystallising a growing awareness of the bogus nature of the “sceptical” position.

Not only have those denying the reality of human-caused global warming lost all credibility but the fallback position of “it’s real but it’s too costly to do anything about it” has also collapsed. There’s ample evidence that the great majority of Australians are willing to pay the modest costs required to stabilise CO2 levels and stop at least the worst consequences of global warming.

* Offset by carbon credits, of course