Most people, at some point or another, when confronted by a vending machine that is supposed to take bills in payment, have had trouble getting it to take a bill. I have a method that has always worked for me. There are two theories as to why it works; I will explain my method in terms of one of these theories.

A vending machine that rejects your bill wishes to thwart you. It infers that you would rather have its product than the bill, and so it would leave you with the bill and deny you the product.

Now, you can keep feeding it the bill until it tires of the game and sells you the product, but who knows how long that might take? Some machines would derive endless pleasure from spitting the bill back at you.

You cannot very well say Oh, I'd rather have this bill than the fizzy sugar water! and, hoping that the machine will be thus fooled, insert the bill. First of all, the machine probably cannot hear you anyway; and, secondly, your actions will in any case speak louder than do your words. It is a given that, at the time that you insert the bill, you would rather have the fizzy sugar water. Hence, you must persuade the machine that you have changed your mind after the insertion of the bill.

You can do this by pulling back on the bill after the rollers have grabbed it. The machine infers that you have just reälized that you won't have enough money for the bus, or have just recognized the bill as a rare collectable. In keeping with its underlying desire to thwart you, it will now hold fast to the bill, pull it inward, and dispense the product.

Feel free to laugh in triumph; as I said, the machine probably cannot hear you anyway.

By way of Mark Mayerson (who got it by way of Journalista),

Clay Shirky on Cognitive Surplus (video 16:30)

The meaningful content here is the audio.

(If the blip.tv link doesn't work for you, then please try Mayerson's entry.)

You'll find it on eBay. Well, that is that you'll find it if it is a tongue-ring barbell using a picture of Che Guevara as one of Bob Marley.

28bytes alerts his readers to the fact that 3 May 2008 is the 30th anniversary of the first piece of spam e.mail.

Although — because spam e.mail can cross national borders — there is a limit to what the Federal government might practically and legitimately do about spam e.mail, the Federal government doesn't do what it could. In fact, Federal legislation actively subverted the efforts of some state legislatures to battle spam.

My suggestion is this: On 3 May of every year, send one piece of email, objecting in your own words (however brief) to poor Federal action against spam, to each of the following:

• your District Representative to Congress
• the two Senators of your State or Commonwealth
• the President
• the Democratic National Committee
• the Republican National Committee

(If one of your Senators is hiding his or her e.mail address, then send e.mail to curator@sec.senate.gov. I don't have a fall-back address for Representatives.)

Encourage each of your acquaintances, friends, and family members who are unhappy about spam e.mail to do the same, and to likewise encourage those whom they know.

This year, there will be very few people sending such objections, but next year there could be substantially more, and the numbers could continue to grow each year.

[Edit (2013:07/17): As part of an SEO programme to get sites to link to Politics.Answers.com, Stuart Hultgren, of Answers.com, contacted me to let me know of a dead link and of a good replacement.]

Last Friday or Saturday, my mother asked me qua economist whether we were in a recession.

I carefully explained to her that the standard formal definition of recession is two or more consecutive quarters of over-all economic contraction. So, as I explained, if I said that we were in a recession then I would be saying that it had contracted in the first quarter of 2008 and would contract in the second quarter, or that it would contract both in the second quarter and in the third quarter.

After that careful prefacing, I told her that I thought that we were in a recession, but that this had to be seen as a guess.

Well, the data have since been reported for the first quarter of 2007, and apparently the economy did not contract, though its annualized growth rate was a sad .6%. My guess is in danger of being falsified, if the growth rate manages to stay at-or-above zero in the present quarter, or if things pull back above zero in the next quarter. Unsurprisingly, I'd be pleased if the data proved me wrong.

In that first quarter, there were those who were mocked for refusing to concede that the economy was in recession. The data demonstrate that it was wrong to mock them. Not that any apologies will be made by those who did the mocking, or even that they will be held to task by other commentators in their circles.

Mind you that a small decline wouldn't have legitimized the mocking. What is wrong, first and foremost, is too much certitude. And then that wrong is compounded by attacking those who are duly cautious.

Given the thrust of most reporting, one might be forgiven for not knowing this, but the earth as a whole seems to have stopped warming for the past four or five years, and in fact seems to have slightly cooled. (And, compared against 1998, it is more clearly cooler.) Of course, we are told that the trend is none-the-less upward.

Now, some proponents of the theory of global warming have even presented a remarkable prediction:

So now a theory of global warming allows for at least a further decade in which temperatures won't actually rise.

For at least the next ten years, no matter what the temperature data say, the theory of global warming isn't to be taken as falsified.

Decades ago, before the typical scientist or engineer had a hand-held, electronic calculator, they used slide rules. And, at some point, jewelers had the thought of making men's jewelry — tie-clips, cuff-links, and what-not — designed to look like slide rules. Well, actually, several designs didn't just look like slide rules; they were slide rules, not very precise, but able to make actual calculations.

A few years ago, I got it into my head to collect working Mannheim slide-rule tie-clips. I believe that, as of to-day, I have secured at least one complete exemplar of every variety of such that was made for resale. You can see some of these sorts included in the Jewelry Slide Rule Archive of Sphere Research's Slide Rule Universe The one sort of working Mannheim slide-rule tie-clip of which I do not have an exemplar was not made for resale, but was given to staff at K&E (an example is in the aforementioned archive). It is sufficiently rare that I have little expectation of getting one.

(BTW, some time ago, the Woman of Interest gave to me a jewelry box specifically so that I would have one suitable for storing and displaying my collection.)

[Addendum (2009:09/23): On 6 May 2008, I retracted this claim, as the slide-ruler tie-clip that I received was actually somewhat different from those that I had seen before (though I have since seen more like it). On 20 July 2009, I made the claim again, and have not felt a need to again withdraw it.]

In various user environments, with various mouses, if one is highlighting within a text field by dragging the mouse from left-to-right, and then moves the mouse just slightly upward, then the highlighting is switched to running leftward from the original cursor position; similarly, if one is highlighting by dragging leftward, and then moves the mouse just slightly downward, then the highlighting is switched to running rightward.

I've observed this behaviour in Linux GUIs and in the Windows XP native GUI; the Woman of Interest tested for me and found this behavior in Mac OS X 10.4. I think that such behaviour is widely standard.

I don't know why mouse software is programmed thus. I don't know why anyone would want a small gesture, easily made by accident, to switch the selection from one set to its complement. In the event of such an accident, if the mouse button has been released then, at the least, one must repeat the highlighting procedure.

In my case, I have repeatedly made such a gesture by accident. In releasing the mouse, so that I can use my right hand to type, I frequently give it a tiny forward push. Since I am generally not watching the screen as I begin typing — my muscle memory is not so good that I will position my right hand properly on the keyboard without looking at the keyboard, and I tend to begin typing before my eyes return to the screen — I often discover that I have over-written text that I had meant to save, and that text that was meant to be replaced is what remains of the original.

Best practice in HTML is to put quotations into Q[uotation] elements, so that the mark-up looks like this:

Sam growled <q>I asked him, and he said <q>I swear on me mother's grave!</q></q>

rather than like this:

Sam growled “I asked him, and he said ‘I swear on me mother's grave!’”

Note that it is possible to have one Q[uotation] element inside of another — a good style-sheet will handle that.

Unfortunately, the WordPress editor seems to have been written by a programmer who believes that Q[uotation] elements must not nest, and the editor tries to fix things when it encounters nesting, by closing the outer element when it comes to the inner element. In the case of my previous entry, it then discarded the original closing </q> tag of the outer element, but (who knows why?) added an extra </div> at the end of the entry. The appearance of the whole page went to H_ll.

I fixed things by by-passing the WordPress software, and editing the 'blog's underlying dB with phpMyAdmin.

I've filed a bug report.

(I still need to arrive at a good specification of the list-bug that plagues my entry on installing Open Office.)

Here, from the BBC, is a bit of rot:

Policy makers will begin their two-day meeting later amid signs that economic growth has stagnated, or even shrunk.

Okay, stagnate means to become unchanging; which is to say that stagnant growth would be a constant growth. Some might perhaps hope for ever-accelerating growth, but most people would be happy with constant growth at, say, 3% to 4% per annum.

There is indeed some concern that the rate of growth has shrunk, but what really concerns people is the possibility that the rate of production (rather than of growth) may have shrunk.

Journalists are just constantly confusing underlying values, first differences, second differences, and so forth. In this case, GDP (or something like it) is our x, growth is Δx/Δt, and the change of the rate of growth is Δ²x/Δt². A stagnant rate of growth would imply

whereäs the fear is that Last year, the Beeb similarly confused the inflation rate with the price level:

The latest inflation rate — or Consumer Prices Index for December as it is formally called — was known to the Bank of England before it made the decision last Thursday to raise interest rates to 5.25%.

(The initial version of the story was even worse, having the title Cost of living at 11-year high. Various parties tried to tried to get the Beeb to fix things, but they just couldn't wrap their heads around the matter.)

This confusion of underlying values and differences is illustrative of the more general problem that the mass of journalists and the mass of their editors just have no understanding of economics, and couldn't sensibly inform the typical reader even if they wanted to do so (and I seriously doubt that they want to do so).