On average I would expect that if my chicken consumption goes down by 1/year, the production of chickens for eating will go down by about 1/year, for the sorts of reasons that erratim gives.
My issue is that there’s a fair amount of waste built in. The chicken you don’t buy is probably just going straight to the rubbish heap. A large supermarket is already throwing away hundreds of pounds of meat each year. For example, British chain Tesco said that in the first six months of 2012, some 28,500 metric tons of their food was wasted. With just under 6,800 stores, that’s over 8 metric tons per store, per year.
To get the retailer to buy less chicken, you’d have to cut consumption enough to exceed their threshold for allowable waste.
I think that “practically zero” means “practically zero as a fraction of the whole, which is true but not directly relevant. (In the same way, donating to a charity that feeds starving people has “practically zero” effect on the problem of starvation, curing someone of cancer has “practically zero” effect on the problem of cancer, etc.)
I meant in absolute terms. If you donate to a charity, that money’s going to help someone. Curing someone of cancer drops the cancer population by one. With chickens, there’s the aforementioned waste problem where you may have to meet certain thresholds before you see any change.
To get the retailer to buy less chicken, you’d have to cut consumption enough to exceed their threshold for allowable waste.
This strikes me as compatible with what gjm said in the sentence before the one you quoted. Some chicken-buying decisions will make no difference, and others are going to have a disproportionate effect by hitting some threshold. In aggregate, chicken purchases by a supermarket have to equal their chicken sales (plus inventory breakage), so a pretty good guess for the expected impact of buying one less chicken is that one less chicken is going to be produced. Richard Chappell discusses a very simple model here. I haven’t seen believable models where in the long run there is substantial deviation from one-for-one.
Yes; another way to think of this is, “How do you model waste?”
If you think waste is best modeled by a fixed percentage of all production, then our best guess about the waste is that it changes proportionally with consumption. We don’t get to magically assign our consumption to the ‘waste’ category without highly specific information (such as, “I found it in a dumpster”).
If you expect the percentage of waste to grow/shrink with industry size, that could be an argument for slightly less/more than 1:1 effect (I’d put it in the “Gains to scale” category, even if it were negative). But I’ve never seen someone make that argument or attempt to model it.
Richard Chappell discusses a very simple model here.
Thanks for sending this; the ‘chunky fallacy’ comes up frequently when discussing this issue. Unfortunately, he explicitly endorses using short term elasticities at the end of his article.
There is undoubtedly some slop built in to the system, both to cover ordinary fluctuations in demand (which is, after all, stochastic), and because inventory control is itself expensive and difficult and only worth doing up to a certain level of precision.
That said, there’s a fallacy here, the same one as in this recent post (addressed here, e.g.). In brief, what matters is not whether you cause stores to waste measurably less food with certainly, but the expected amount of change in food waste due to your actions, especially over the long term.
My issue is that there’s a fair amount of waste built in. The chicken you don’t buy is probably just going straight to the rubbish heap. A large supermarket is already throwing away hundreds of pounds of meat each year. For example, British chain Tesco said that in the first six months of 2012, some 28,500 metric tons of their food was wasted. With just under 6,800 stores, that’s over 8 metric tons per store, per year.
To get the retailer to buy less chicken, you’d have to cut consumption enough to exceed their threshold for allowable waste.
I meant in absolute terms. If you donate to a charity, that money’s going to help someone. Curing someone of cancer drops the cancer population by one. With chickens, there’s the aforementioned waste problem where you may have to meet certain thresholds before you see any change.
This strikes me as compatible with what gjm said in the sentence before the one you quoted. Some chicken-buying decisions will make no difference, and others are going to have a disproportionate effect by hitting some threshold. In aggregate, chicken purchases by a supermarket have to equal their chicken sales (plus inventory breakage), so a pretty good guess for the expected impact of buying one less chicken is that one less chicken is going to be produced. Richard Chappell discusses a very simple model here. I haven’t seen believable models where in the long run there is substantial deviation from one-for-one.
Yes; another way to think of this is, “How do you model waste?”
If you think waste is best modeled by a fixed percentage of all production, then our best guess about the waste is that it changes proportionally with consumption. We don’t get to magically assign our consumption to the ‘waste’ category without highly specific information (such as, “I found it in a dumpster”).
If you expect the percentage of waste to grow/shrink with industry size, that could be an argument for slightly less/more than 1:1 effect (I’d put it in the “Gains to scale” category, even if it were negative). But I’ve never seen someone make that argument or attempt to model it.
Thanks for sending this; the ‘chunky fallacy’ comes up frequently when discussing this issue. Unfortunately, he explicitly endorses using short term elasticities at the end of his article.
Exactly.
There is undoubtedly some slop built in to the system, both to cover ordinary fluctuations in demand (which is, after all, stochastic), and because inventory control is itself expensive and difficult and only worth doing up to a certain level of precision.
That said, there’s a fallacy here, the same one as in this recent post (addressed here, e.g.). In brief, what matters is not whether you cause stores to waste measurably less food with certainly, but the expected amount of change in food waste due to your actions, especially over the long term.