erratim comments on How much does consumption affect production? - Less Wrong

4 Post author: erratim 05 January 2015 03:51PM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (60)

You are viewing a single comment's thread. Show more comments above.

Comment author: Furslid 09 January 2015 06:56:58AM *  0 points [-]

Cumulative elasticity = Supply Elasticity/(Supply Elasticity - Demand Elasticity).

A cumulative elasticity factor of one means a demand elasticity of 0.

A completely inelastic demand curve is not to be expected in standard economics, and as such it is an inappropriate prior. Thanks for the math demonstrating my point.

Comment author: erratim 09 January 2015 12:49:13PM 0 points [-]

Cumulative elasticity = Supply Elasticity/(Supply Elasticity - Demand Elasticity). A cumulative elasticity factor of one means a demand elasticity of 0.

I believe your math skipped a step; it seems like you're assuming that Supply Elasticity is 1. I actually claim in the original article that "the 'price elasticity of supply' in the arbitrarily long term becomes arbitrarily high". In other words, as "length of 'term'" goes to infinity, the Supply Elasticity also goes to infinity and the cumulative elasticity factor approaches 1 for any finite Demand Elasticity.

Thanks for the math demonstrating my point.

Stepping back, I worry from your sarcastic tone and the reactive nature of your suggestions that you assume that I am trying to 'beat you' in a debate, and that by sharing information that helps your argument more than it helps mine, I have made a mistake worthy of mockery.

Instead, I am trying to share an insight that I believe is being overlooked by the 'conventional wisdom' of this community and is affecting multiple public recommendations for rational behavior (of cost/benefit magnitude ~2x).

If I am wrong, I would like to be shown to be so, and if you are wrong, I hope you also want to be corrected. If instead you're just debating for the sake of victory, then I don't expect you to ever be convinced, and I don't want to waste my effort.

Comment author: erratim 09 January 2015 12:52:39PM 1 point [-]

Oops, I meant to edit that rather than retract. Since I don't believe there's a way to un-retract I'll re-paste it here with my correction (Changing "Supply Elasticity is 1" to "Supply Elasticity is finite"):

Cumulative elasticity = Supply Elasticity/(Supply Elasticity - Demand Elasticity). A cumulative elasticity factor of one means a demand elasticity of 0.

I believe your math skipped a step; it seems like you're assuming that Supply Elasticity is finite. I actually claim in the original article that "the 'price elasticity of supply' in the arbitrarily long term becomes arbitrarily high". In other words, as "length of 'term'" goes to infinity, the Supply Elasticity also goes to infinity and the cumulative elasticity factor approaches 1 for any finite Demand Elasticity.

Thanks for the math demonstrating my point.

Stepping back, I worry from your sarcastic tone and the reactive nature of your suggestions that you assume that I am trying to 'beat you' in a debate, and that by sharing information that helps your argument more than it helps mine, I have made a mistake worthy of mockery.

Instead, I am trying to share an insight that I believe is being overlooked by the 'conventional wisdom' of this community and is affecting multiple public recommendations for rational behavior (of cost/benefit magnitude ~2x).

If I am wrong, I would like to be shown to be so, and if you are wrong, I hope you also want to be corrected. If instead you're just debating for the sake of victory, then I don't expect you to ever be convinced, and I don't want to waste my effort.

Comment author: Furslid 09 January 2015 05:28:17PM 1 point [-]

I'm sorry, that is correct. You were describing a supply curve that doesn't behave normally. So I can't say anything about demand curves. I apologize for the cheap shot.

In the standard economic models, supply and demand curves have elasticity that is a positive, finite number. Infinitely elastic curves are not possible within the standard models.

The priors I start with, for any market, are that it behaves in a manner consistent with these economic models. The burden of proof is on any claim that some market is behaving in a different manner.

Comment author: erratim 09 January 2015 08:54:25PM 1 point [-]

Thanks for acknowledging that.

I think standard economics agrees with your vision of "~always positively-sloping finite supply curves" in the short term, but not necessarily the long term. Here's a quote from AmosWEB (OK, never heard of them before, but they had the quote I wanted)

As a perfectly competitive industry reacts to changes in demand, it traces out positive, negative, or horizontal long-run supply curve due to increasing, decreasing, or constant cost.

Comment author: Furslid 11 January 2015 05:08:30PM 1 point [-]

Long term supply curves are different than supply curves. They are similarly named, but different concepts.

Supply curves measure supply at a price.

Long term supply curves measure market equilibrium supply as demand changes over time.

The elasticity measurement is the derivative of supply with respect to price. It cannot be applied to long term supply curves.

Comment author: erratim 15 January 2015 07:17:22AM 0 points [-]

I agree with your definitions of the two curves, although I don't know what point you're making by the distinction.

In either case we can ask, "how much will changes in demand affect equilibrium quantity?" In a constant-cost industry, the answer will be 1:1 in the long-run (as indicated by a flat, or infinitely elastic long-run supply curve), but as you gradually shorten the scope over which you're looking at the market, making it a shorter- and shorter-run supply curve, it will steepen (elasticity decrease) such that the answer is "less than 1:1".

Comment author: Furslid 16 January 2015 03:15:55AM *  0 points [-]

First, is that because they are different things it's not a contradiction to what I said.

The second is that elasticity is not validly applied to long term supply curves, as they are not a function of supply in terms of price.