Tuesday, September 22, 2009

Did Carl Sagan Libel Christiaan Huygens?

"Consider the curious argument by which he deduced the existence on Jupiter of hemp. Galileo had observed four moons traveling around Jupiter. Huygens asked a question of a kind few astronomers would ask today: Why is it that Jupiter has four moons? Well, why does the earth have one moon? Our moon’s function, Huygens reasoned, apart from providing a little light at night and raising the tides, is to aid mariners in navigation. If Jupiter has four moons, there must be as many mariners on that planet. Mariners imply boats; boats imply sails; sails imply ropes. And ropes imply hemp. I sometimes wonder how many of our own prized scientific arguments will appear equally foolish from the vantage of three centuries." (From a Scientific American article by Carl Sagan)

I came across a reference to this claim in an online conversation and got curious enough to google for it. All of the references I found were suspiciously similar, suggesting that they all were based on the same source. I eventually concluded that the source was Sagan. None of them provided any evidence for the story in anything Huygens had written.

So I want looking and found a webbed translation of Cosmotheoros, a treatise on matters astronomical written by Huygens late in his life. It's an interesting work, combining what appears to be an accurate account of astronomical knowledge of the time with lengthy speculations about possible inhabitants of other planets. Huygens, living more than a century before Darwin, takes it for granted that living creatures are the result of divine design and, logically enough, tries to figure out whether and how a benevolent God would have populated other planets. That seems a bit odd to the modern reader, but the author makes it clear that what he is offering is speculation. There are lots of references to Jupiter and one to hemp, but nothing that even comes close to supporting Sagan's story.

Huygens writes, with reference to Jupiter and Saturn:

"This Position of the Moons, in respect of their Planets, must occasion great many very pretty, wonderful sights to their Inhabitants, if they have any: which is very doubtful, but may for the present be suppos'd."

Which does not sound like a statement from someone with the view of the subject that Sagan attributes to Huygens.

I see three possibilities:

1. I have somehow missed, in Cosmotheoros, the passage on which Sagan bases his story. I think that very unlikely; I haven't read the whole treatise, but it is webbed with a search engine.

2. Sagan is accurately reporting something Huygens wrote elsewhere, perhaps a theory he had rejected by the time he wrote the treatise.

3. Sagan's story is false. Either he is deliberately lying for the sake of telling an entertaining story about how foolish people were in the past or he never bothered to check something he misremembered or got from someone else.

I favor alternative 3, but perhaps one of my readers can provide evidence for one of the others. If the story is based on something Huygens wrote I suspect, after looking through Cosmotheoros, that Sagan is misrepresenting a speculation as a claim.

Facts Don't Speak For Themselves

Suppose, optimistically, that a year from now the current recession is currently over, the economy more or less returned to normal. There are two opposite ways in which recent events can be, and will be, interpreted:

1. The U.S. faced the risk of another Great Depression and was saved from it only by the prompt and courageous action of the Obama admnistration, in the form of stimulus and bailouts.

2. The U.S. was going into a recession, as from time to time it does. The Obama administration used exaggerated rhetoric to misrepresent it as an impending catastrophe in order to justify an extraordinary increase in government spending financed by enormous deficits. The money was mostly spent on the sorts of things politicians like to spend money on. The combined effect of rhetoric and policy made the recession more serious than it would otherwise have been but it still ended, perhaps a little later than it otherwise would have.

Both versions are, I think, consistent with the casual evidence available to most voters. Is there any basis, other than preexisting political preferences, by which voters can choose between them?

Thursday, September 17, 2009

Arctic Sea Ice: Latest Figures

Regular readers of this blog will remember a series of posts (the three links are to three different posts) a few months back dealing with the question of whether NASA/JPL was lying when they claimed on a JPL web page that:

"The latest Arctic sea ice data from NASA and the National Snow and Ice Data Center show that the decade-long trend of shrinking sea ice cover is continuing."

I argued at the time that the latest data actually showed the shrinking to have reversed, although there was no way of knowing if that was more than a temporary deviation. The discussion got me into a correspondence first with someone at NASA who turned out to be a publicity person not a scientist, then with a scientist at NSDIC. It also resulted in a lot of comments on this blog.

Out of curiousity, I checked back today on the NSDIC web page, and found:

"The 2009 minimum is the third-lowest recorded since 1979, 580,000 square kilometers (220,000 square miles) above 2008 and 970,000 square kilometers (370,000 square miles) above the record low in 2007."

Or in other words, the extent of arctic sea ice has been increasing for the last two years, contrary to the claim I quoted above. The NSDIC puts the result in a way that emphasizes the fact that it is still below its long term level and obscures the fact that, for the past two years, arctic sea ice extent has been going up, not down. But at least they tell the truth about the facts.

To avoid irrelevant comments, I am not arguing for or against claims that the greater extent doesn't really count because it is thinner ice or that all the evidence taken together still supports long term shrinking of arctic sea ice. My claim is simply that the quote above, which is still up on the JPL web page, is false. When people lie to me about the evidence for their conclusions, offering other evidence that their conclusions are still true is not an adequate defense.

Tuesday, September 15, 2009

For Your Own Good

An Australian navy ship has intercepted a boat carrying nearly 60 suspected asylum seekers - the fourth such incident in less than two weeks.

"Situations around the world mean that large numbers of displaced persons are looking for settlement in wealthy, developed nations like Australia and can be targeted by, and fall prey to, people-smugglers," Australian Home Minister Brendan O'Connor said." (Recent news story)

From the standpoint of the asylum seekers, O'Connor and the Australian navy are the enemy. The "people smugglers" are the ones on their side, the people who, for a price, are trying to get them into Australia. O'Connor is trying to keep them out. In an attempt to obscure that fact, he describes the situation as the immigrants "falling prey to" the people smugglers.

I am reminded of President Clinton's explanation that the reason he was having the U.S. coastguard turn back people trying to escape from Haiti to the U.S. was for their own good, the crossing being a dangerous one. That was the point at which I decided that, whatever his qualifications as a President, Clinton was a pretty poor excuse for a human being. Stopping desperate people from escaping from their particular hell may, under some circumstances, be excusable. Pretending that you are doing it for their good is not.

If only there had been enough more of those wicked people smugglers in the late thirties for desperate emigrants to fall prey too, it might have been only five million.

Saturday, September 12, 2009

International Health Care Comparisons: The WHO Numbers

In the course of the healthcare debate, supporters of change along the lines proposed by the administration have called attention to a World Health Organization study ranking the health care systems of 192 nations. A common claim is that the U.S., despite spending more per capita than any other country, still ranks only 37, behind most developed countries.

That version of the claim is at best misleading. There is a measure, "Overall Health System Performance," on which the U.S. ranks 37. But it is a measure that takes expenditure into account, downrating the U.S. precisely because it spends so much. The rank is 37 not in spite of the level of expenditure but because of it.

There is another measure, "Overall Goal Attainment," which does not take account of expenditure; on that the U.S. ranks 15, still behind a fair number of other countries but not nearly as many. So a more accurate claim would be that the U.S. ranks 15 despite its large expenditures.

Even that is misleading, however, because if one actually read the notes explaining how the numbers are calculated it turns out that "Goal Attainment" is based on five different characteristics of a health care system, only one of which is an (imperfect) measure of how much health care the system provides.

That one, "Health level," is average life expectancy, adjusted to make a disabled year count for less than a healthy year. It is an imperfect measure because life expectancy depends not only on health care but on lifestyle variables such as smoking or obesity and on factors such as the death rate from murders and traffic accidents. And even to the extent that it depends on health, health is not entirely a matter of health care; some environments are more unhealthy than others.

A second variable, responsiveness, measures how good people in each country think their health care system is, as determined by questionaires. On that one, interestingly enough, the U.S. comes in first—a fact that ought to worry the President. If Americans think the current system works better than any existing alternative, as they apparently do, they may not look favorably on changes to it.

The other variables all have to do with distribution. "Health distribution" purports to measure how unequal the distribution of health care in each country is. The authors wanted to use distribution of life expectancy but didn't have the data to do it. Instead they used a measure, never clearly explained, of the distribution of infant survival, apparently of how many infants die at what point in their first five years. Even for that, the relevant data existed for only a minority of countries; for the rest the report substituted an estimate based on variables such as poverty level.

"Responsiveness distribution" was calculated from questionaires and apparently designed to measure the degree to which respondents believed that various groups in their country were disadvantaged with regard to health care.

Finally, we have "fairness in financial contribution," defined as how nearly health costs are distributed in proportion to income minus the cost of food. That measure is obviously biased in favor of state run health care plans, since in order for both health care and its cost to be distributed in the way the authors of the report want there has to be a sizable redistribution of cost from poorer families getting health care to richer families paying for it.

My conclusion is that the numbers produced by the report are very nearly useless for purposes other than propaganda, since they do not provide much information on how good the health care systems of different countries are at delivering health care.

In fairness, I should add that I don't have any proposal for doing a much better job of comparing international health care systems, given the data limitations when trying to look at 192 different countries. Ideally, one would want a value added measure, something like the difference between actual life expectancy in a country and what life expectancy would be if there were no health care system at all. But I don't see any practical way of generating such numbers. One could simply use life expectancy, but that has the problems I have already described. One can try to look at particular outcomes heavily dependent on health care; the U.S. apparently does very well measured by cancer survival rates. But neither approach really tells you what you want to know.

Obama Supports Vouchers

for healthcare.

At least, that's how I interpret the descriptions I have seen of his current plan, although I gather any interpretation is pretty uncertain at this point. He appears to be proposing:

1. That everyone be required to have health insurance.

2. That low income consumers get their health insurance subsidized.

3. That there be a "public option" that is not subsidized.

Combine those, and it looks as though low income consumers are getting a voucher that they can spend on either private or public health insurance. That's almost precisely the plan that Obama rejected for schooling when he decided to cancel the D.C. voucher experiment. The only differences are that, in the schooling case, there was still a net subsidy to the "public plan," since the amount of the voucher was less than the per pupil expenditure in the public schools, and that in the health plan, some consumers will be paying part of the cost of the public plan with their own money.

Monday, September 07, 2009

Dreaming as Virtual Reality

In the chapter on virtual reality in my Future Imperfect I suggested that if we could crack the dreaming problem, figure out how dreaming works, we could create a much richer form of virtual reality, sending sensory signals to the brain instead of merely beaming photons at the eyes and sound waves at the ears. Implicit in this idea is the assumption that dreaming really is a rich form of virtual reality, creating a full illusion of real sensations.

I woke up from dreams several times last night and tried to remember what they were like. It is hard to be certain, since my dream memories fade rapidly, but I do not think they were full sense VR or anything close. I remember only one color from any of them, and it was wrong, a more intense version of the color of what I was dreaming about. My overall impression was that dreaming is more like reading a book than like watching a movie, that in the dream you know certain things are happening but you are not actually seeing, hearing, feeling those things in the way you would if they were happening in real life.

Is this consistent with other people's observations? Anyone aware of research into the nature of dreaming along these general lines?

Saturday, September 05, 2009

Implications of a Doomed Dollar

My friend Jeff Hummel has been arguing for some time that the U.S. is eventually going to default on its debt. Central to his argument is the fact that an increase in the perceived risk of default increases the risk premium the U.S. has to pay to lenders. Since the debt is large (and rapidly getting larger) an increase in the interest rate the U.S. has to pay results in significantly increased budgetary problems, which results in an increased risk of default, which results in a further increase in the risk premium—a positive feedback mechanism. I do not know if his prediction is correct, nor do I know whether, if it is, default would be via repudiation or inflation, but it is at least an interesting argument.

I was reminded of it recently when I received an Email from The Motley Fools, investment advisers who for some reason have me on their mailing list. The title is "Read This Because the Dollar is Doomed." The authors argue that the U.S. trade deficit, the U.S. budget deficit, and the willingness of the U.S. to pay for things by printing money all threaten the dollar. They conclude that "This should be worrisome news if you earn a dollar-based salary, keep a dollar-based bank account, or invest in dollar-denominated U.S. stocks and bonds. Why? Because as the dollar declines in value, so too will all of your earnings, savings, and investments. And that's scary stuff." They argue that the solution is to invest in "stocks that do business in other currencies ... and specifically in currencies that you suspect will rise against the dollar over time."

It is possible that the dollar is doomed, but their explanation and advice confuse two different issues—price levels and exchange rates. Inflation due to too much money creation is a problem if you have assets whose value is fixed in dollars, such as T-bills. But it isn't a problem for assets whose value is merely measured in dollars, such as U.S. stocks. If all prices double, the price of Apple computers doubles too, as does the value of Apple stock. Some companies will do better in an inflation than others, in part because some companies have assets or liabilities whose dollar value is fixed. But that has nothing to do with whether the company's stock is dollar denominated.

Nor does it have anything to do with whether the company does business in other currencies. If the value of the dollar drops and the value of the Euro doesn't, then the dollar value of a company that does business in Euros will go up. But so will the dollar value of a company that does business in dollars. The Euros the company is earning exchange for more dollars than they used to, but those dollars are worth less.

There is, however, a different sense in which the dollar might be doomed, with different implications for investors.

Suppose the U.S. price level stays the same but the exchange rate between dollars and other currencies falls. A dollar will still buy the same goods and services in the U.S. as before, but not as many Euros or Yen or Rupees.

Why might that happen? The market exchange rate between the Euro and the dollar is the price at which the number of dollars that people want to sell for Euros equals the number that other people want to buy. One reason to trade Euros for dollars is in order to buy goods in the U.S. and ship them back to Europe, and similarly in the other direction. If that is all that is happening the exchange rate ought to reflect the purchasing power of the currencies, with some complications due to the fact that not all goods and services play a role in international trade.

Another reason a European might want dollars, however, is in order to buy T-bills—more generally, in order to buy U.S. capital assets. If the U.S. is running a large budget deficit, as it is, and if much of that money is being borrowed from foreigners, as it is, then a lot of dollars are being bought in order to lend them to the U.S. government. That additional demand bids up the price of the dollar in exchange markets. The capital inflow appears in the statistics as a trade deficit, since some of the foreign goods the U.S. is importing are being exchanged for capital assets which remain in the U.S. rather than for export goods that don't.

Suppose foreigners decide that lending money to the U.S. government is no longer prudent. That part of the demand for dollars vanishes. The price of the dollar measured in Euros or Rupees falls. Some of the foreigners who have lent money to the U.S. decide it was a mistake, cash in their T-Bills for dollars, and trade those dollars for Euros or Rupees. That increases the supply of dollars on the foreign exchange market, driving the dollar down even farther. The Motley Fool isn't entirely clear about which sort of decline of the dollar he is talking about but one could, with a little effort, take his references to the trade deficit and the budget deficit as suggesting some mechanism along these lines.

What are the implications if the dollar maintains its value domestically but falls in its exchange rate? Americans who hold assets with fixed dollar values are unaffected, except to the extent that they want foreign currency, perhaps for a Paris vacation. Americans who hold stock in foreign companies, or in U.S. companies whose income is largely in foreign currencies, benefit, since their stock is now worth more dollars. The losers this time are foreigners who made the mistake of holding U.S. assets.

It is, perhaps, unreasonable to expect investment advisers to not only understand economics but to explain it correctly to their customers. On the other hand, since which part of their advice one ought to follow depends on what sort of doom the dollar is facing, it would be nice if they at least tried.