Have you ever heard the question “Would you like a tea or a coffee” answered with a simple “Yes”? If so, the respondent almost certainly considers their response to be extremely witty. The questioner is unlikely to agree. There is also a high probability that the joker is someone’s Dad…or perhaps a mathematician.

I have to admit to having indulged in this “joke” in my time (more than once), but until recently it had not occurred to me that it in fact reflects a violation of a general principle of conversation. Enlightenment came when I read the seminal 1975 paper “Logic and Conversation” [1] by the philosopher H.P.Grice.

The humour (or lack thereof) of the coffee/tea gag lies in the conflict between the logical truth of the statement and its inappropriateness in conversation. While the statement “A or B” is logically true as long as at least one of A and B is true , in the context of conversation, logical truth is not enough. If you knew A was true and B was false, you would not bother saying “A or B”, you would just say “A”. Moreover, that is what others would expect of you. If I ask you to pass me a hammer, I don’t expect you to pass me a hammer and a spanner. In the same way, if you know you are going to Spain for your holidays, I don’t expect you to say “I’m either going to Spain or Canada”, despite the fact that, strictly speaking, it is a true statement. It is this distinction between simple logical truth and appropriateness in conversation that is the subject of Grice’s paper.

Grice bases his ideas on the notion of the “Cooperative Principle”, which he summarises as the requirement to

Make your conversation such as is required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged.

People have conversations of many types for many reasons: to do business, to gossip, to seduce, to educate, to inform or simply for the pleasure of conversation itself. In every case, conversation involves (at least) two participants and the conversations that work best are the ones that take the needs of all of the participants into account. So it makes sense that a bit of cooperation is the foundation of a good conversation.

Based on the cooperative principle, Grice goes on to postulate a number of “maxims of conversation”. Here are the maxims as he describes them:

Quantity

  1. Make your contribution as informative as is required (for the current purposes of the exchange).
  2. Do not make your contribution more informative than is required.

Quality

  1. Do not say what you believe to be false.
  2. Do not say that for which you lack adequate evidence.

Relation

  1. Be relevant.

Manner

  1. Avoid obscurity of expression.
  2. Avoid ambiguity.
  3. Be brief (avoid unnecessary prolixity).
  4. Be orderly.

The term “maxim” is carefully chosen as Grice notes that one need not follow all of the maxims at all times, while still being cooperative. The main reason that a maxim could be violated is if it is in conflict with another maxim. An example would be providing less information than required (violating Quantity 1) because you are not confident you have the facts right (and you don’t want to violate Quality 2).

Viewed in terms of Grice’s maxims, the coffee/tea joke is a clear violation of the first maxim of quantity.

As I have already admitted to this particular breach, the obvious question is: have I violated any other maxims? Some who know me well would take the view that, while I may take pains to avoid a violation of either of the maxims of quality, I regularly and flagrantly violate Quantity 2 and Manner 3 and probably Relation 1. I need to learn to stick to the point or risk being branded an uncooperative conversationalist! Or perhaps it’s too late.

[1] Available in the collection “Studies in the Way of Words” by H.P.Grice.

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Yesterday’s Sydney Morning Herald featured an opinion piece by Rodney Tiffen on Australia’s sluggish response to climate change. Deliberately provocative, the discussion was framed from the outset in the language of competition:

An international competition in self-righteousness would be closely fought. But Australia must be a strong contender.

Tiffen went on to draw on data from the International Energy Agency (IEA), but got his statistics slightly wrong in the process:

If we restrict the analysis to the most populous 130 countries, those with a population of 3.5 million or more, Australia is the world leader. Only a handful of small countries, especially oil producers such as Bahrain, Qatar and Kuwait, have higher per person emissions.

Australians may be disappointed to learn that we do not, in fact, take home the trophy in this competition. Both the United Arab Emirates and the United States have populations over 3.5 million and have higher per capita emissions than Australia at last count (2007). Nevertheless, coming in third place in this competition, Australia certainly punches above its weight, with per capita emissions running at 4.3 times the world average. Furthermore, as the chart below shows, we have been steadily catching up to the United States over the last 40 years. In fact, to give Tiffen the benefit of the doubt, the most recent IEA data is for 2007, so we may well be ahead of the USA by now.

CO2 emissions 1971-2007 (Source: IEA)

The reason Tiffen looks at per capita emissions is to ward off one common argument for inaction on climate change, namely that China and the United States are the only countries that can make a difference. There is no doubt that these two countries dominate the overall production of emissions. Throwing Canada and Mexico in with the United States brings North American emissions to almost one quarter of the world’s total. Add China and almost half the world’s emissions are accounted for.

Total CO2 emissions for 2007 (Source: IEA)

Nevertheless, if the aim is to attempt reductions in world emissions, Tiffen’s focus on per capita emissions is entirely appropriate. No-one would be convinced if the United States viewed its emissions along State lines, thereby arguing that their emissions were not so big by global standards after all (although, this defence would probably not be much use to California). While countries may be actors on the world stage through their political proxies at climate conferences, emissions are ultimately the product of people (both at home and at work) and not countries. Ranking countries by per capita emissions is thus useful as it gives some indication of where emission reductions may be more readily achieved. The chart below shows the top 25 (big and small) countries in terms of per capita emissions.

Top 25 per capita emitters for 2007 (Source: IEA)

Qatar ranks so high on this scale that it compresses the figures for all of the emitters below it, so here is the chart again with a somewhat truncated scale.

Top 25 per capita emitters for 2007 (Source: IEA)

There are certainly some small countries with high rates of carbon emissions per capita, but looking at a larger scale reveals that developed countries are the worst in per capita terms. It is worth noting, though, that Europe is doing better than the rest of the OECD and is also ahead of former members of the Soviet Union.

Per capita emissions by region for 2007 (Source: IEA)

Another useful approach is to consider emissions per dollar of economic output. This serves to highlight “inefficient” emitters, not to shame them but to identify where spending money on the problem is most likely to deliver significant results. It should come as no surprise that a league table of the highest emitters per dollar of gross domestic product (GDP) is a catalogue of troubled and/or small nations. Note that these figures are calculated based on conversion to US dollars using market exchange rates. Using purchasing power parity instead does reorder the list somewhat, but the names are largely the same.

Top 25 emitters by emissions/GDP for 2007 (Source: IEA)

This perspective suggests that when developed countries consider programs to assist developing countries to reduce their emissions, they could reasonably focus on significant but inefficient emitters. The chart below provides a possible target list, showing the 10 worst-performing countries in terms of emissions per dollar of economic output after restricting to countries with emissions of at least 150 million tons of C02 per annum.

Top 10 large emitters by emissions/GDP for 2007 (Source: IEA)

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When will Julia go to the polls?

2 July 2010

After taking Kevin Rudd’s scalp and now having done a deal with the miners, Australia’s new prime minister, Julia Gillard, is widely expected to call an early poll. The question is, when will the election be held?

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RSPT RIP – Long Live the MRRT

2 July 2010

In the third in a series of guest posts on the subject of Australian mining tax, Zebra (James Glover) considers the changes to the proposed tax the new prime minister, Julia Gillard, has negotiated with miners.

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Surf

25 June 2010

A new R user group has launched in Sydney.

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The Monty Hall Problem

21 June 2010

A look at the famous and controversial probability puzzle, the Monty Hall problem. Cars or goats anyone?

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High-frequency trading

15 June 2010
Mule Variations

Is high-frequency trading a great innovation that improves the efficiency of the market, or is it something we should be worried about?

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RSPT – A Fair Valuation Based on True Value of New and Existing Mines

12 June 2010

Guest author James Glover takes another look at the resources tax and concludes that the tax for existing mines should be lower.

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Eliminating the irrelevant

10 June 2010

Part two of the “Tuesday’s Child” probability puzzle: why I think that the classical solution is wrong.

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Tuesday’s Child

8 June 2010

Following on from the teasers in the probability paradoxes post, here is a closer look at “Tuesday’s child”. While it may not strictly be a paradox, it still has the rich potential for generating controversy.

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