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I'm always fascinated when someone mentions a paradox so I looked up "Jevon's Paradox". The real economic term for this is elastic demand (specifically, relati

I'm always fascinated when someone mentions a paradox so I looked up "Jevon's Paradox". The real economic term for this is elastic demand (specifically, relatively elastic demand). For example, microprocessor cost reductions make new applications possible, thus demand increased so much that the total amount spent on microprocessors went up for decades. Example of inelastic demand is radial tires. They last four times as long as bias ply tires. But since this didn't cause people to drive four times further, the tire industry collapsed on the introduction of radial tires. Does anyone know an example of an actual paradox? I've never found one, and I'm curious if they really exist.

zenlikethat 10y ago
Are you sure? Jevons's Paradox is about demand increasing for a resource when it becomes more efficient to use, e.g., someone invents an engine which can go twice as far with the same amount of fuel but instead of halving the demand for fuel the demand actually increases. If I recall, elasticity of demand has to do with the relationship to supply. A very inelastic demand will cause people to consume the same rate no matter how much _supply_ is available. It doesn't have to do with the efficiency at which the resource is consumed like stated above. It's a subtle difference but I think they're actually quite distinct concepts. Actual paradoxes are common. Just consider the classic: "This sentence is false".
- paulsutter 10y ago
  Yes I'm sure. When coal becomes cheaper as a fuel (efficiency being one path), if that opens up new applications or use by a broader set of customers, it's no surprise at all that total revenue could go up. As for your example, most sentences are neither true nor false. Nothing interesting has a probability of 0.000 or 1.000. "This sentence is false" is clever use of language, may be interesting to sophomore philosophy students while smoking weed, but its not useful and there's nothing paradoxical about it.
  - jholman 10y ago
    Regarding your question about a paradox, what would qualify to you as "an actual paradox"? What is the definition against which you try a contender? Free free to look it up in a dictionary, but that probably won't help you generate a definition that makes "This statement is false" non-paradoxical. Note also that the etymology of paradox is "beyond strange", so historically the bar for qualifying is simply to be a idea or combination of ideas that is remarkably strange or surprising. > most sentences are neither true nor false. Nothing interesting has a probability of 0.000 or 1.000. I'll start by observing that surely you're talking about propositions, not sentences, nor utterances. Or at least you ought to be. But more significantly, I'll note that most propositions are either true or false (under a given interpretive framework), but that as epistemologically-unprivileged observers, we must assign empirical propositions probabilities that are higher than 0 and lower than 1. Propositions like "I am a fish" or "You hate meat" or "If Rosa hates meat then Alexis is a fish" are either true or false, under any given set of meanings for the constituent words (objects, predicates, etc). I'm curious what probability you think applies to propositions like "2 + 2 = 4" and "All triangles have 3 sides" and "All triangles have less than 11 sides". I think there are very many interesting propositions that differ from these only in degree of complexity (e.g. propositions about whether or not certain code, run on certain hardware, under certain enumerable assumptions about the runtime, will do certain things). Based on your very strange claim that all interesting sentences have non-zero non-unity probability, perhaps you're saying that you find theorems uninteresting, and moreover are only interested in statements of empirical belief, such as "I put the odds of the sun failing to rise tomorrow lower than one in a billion." In that case, I cannot imagine what statement interest would qualify as a paradox, except perhaps insofar as some empirical statements of belief are "beyond strange". "This sentence is false" is a paradox under pretty much everyone's notion of a paradox.
    - paulsutter 10y ago
      > I'm curious what probability you think applies to propositions like "2 + 2 = 4" and "All triangles have 3 sides" and "All triangles have less than 11 sides". Those are great examples, thanks. All true, and there's nothing interesting about them.
inimino 10y ago
An actual paradox is an apparent paradox that you don't know how to resolve.
bradleyjg 10y ago
"This statement is not true."
- late2part 10y ago
  "This statement is true, not."

zenlikethat 10y ago

Are you sure? Jevons's Paradox is about demand increasing for a resource when it becomes more efficient to use, e.g., someone invents an engine which can go twice as far with the same amount of fuel but instead of halving the demand for fuel the demand actually increases. If I recall, elasticity of demand has to do with the relationship to supply. A very inelastic demand will cause people to consume the same rate no matter how much _supply_ is available. It doesn't have to do with the efficiency at which the resource is consumed like stated above. It's a subtle difference but I think they're actually quite distinct concepts. Actual paradoxes are common. Just consider the classic: "This sentence is false".

paulsutter 10y ago
Yes I'm sure. When coal becomes cheaper as a fuel (efficiency being one path), if that opens up new applications or use by a broader set of customers, it's no surprise at all that total revenue could go up. As for your example, most sentences are neither true nor false. Nothing interesting has a probability of 0.000 or 1.000. "This sentence is false" is clever use of language, may be interesting to sophomore philosophy students while smoking weed, but its not useful and there's nothing paradoxical about it.
- jholman 10y ago
  Regarding your question about a paradox, what would qualify to you as "an actual paradox"? What is the definition against which you try a contender? Free free to look it up in a dictionary, but that probably won't help you generate a definition that makes "This statement is false" non-paradoxical. Note also that the etymology of paradox is "beyond strange", so historically the bar for qualifying is simply to be a idea or combination of ideas that is remarkably strange or surprising. > most sentences are neither true nor false. Nothing interesting has a probability of 0.000 or 1.000. I'll start by observing that surely you're talking about propositions, not sentences, nor utterances. Or at least you ought to be. But more significantly, I'll note that most propositions are either true or false (under a given interpretive framework), but that as epistemologically-unprivileged observers, we must assign empirical propositions probabilities that are higher than 0 and lower than 1. Propositions like "I am a fish" or "You hate meat" or "If Rosa hates meat then Alexis is a fish" are either true or false, under any given set of meanings for the constituent words (objects, predicates, etc). I'm curious what probability you think applies to propositions like "2 + 2 = 4" and "All triangles have 3 sides" and "All triangles have less than 11 sides". I think there are very many interesting propositions that differ from these only in degree of complexity (e.g. propositions about whether or not certain code, run on certain hardware, under certain enumerable assumptions about the runtime, will do certain things). Based on your very strange claim that all interesting sentences have non-zero non-unity probability, perhaps you're saying that you find theorems uninteresting, and moreover are only interested in statements of empirical belief, such as "I put the odds of the sun failing to rise tomorrow lower than one in a billion." In that case, I cannot imagine what statement interest would qualify as a paradox, except perhaps insofar as some empirical statements of belief are "beyond strange". "This sentence is false" is a paradox under pretty much everyone's notion of a paradox.
  - paulsutter 10y ago
    > I'm curious what probability you think applies to propositions like "2 + 2 = 4" and "All triangles have 3 sides" and "All triangles have less than 11 sides". Those are great examples, thanks. All true, and there's nothing interesting about them.

inimino 10y ago

An actual paradox is an apparent paradox that you don't know how to resolve.

bradleyjg 10y ago

"This statement is not true."

late2part 10y ago
"This statement is true, not."