Apr 14 2011

Self-interest and electoral perversions

In this post I will argue that all of the political parties are arguing the case for AV in their own self-interest, this is very obviously what they are doing and admitting such will make a change.

I’d like to start with the electoral system as it stands today:

Two things are going on at an a general election: there are “local” elections in 650 constituencies which determine which individual represents each constituency in parliament and then there is the government formed as the result of this set of elections. Once elected to parliament MP’s represent their constituents interests but vote largely as whipped by their political party.

First past the post (FPTP) and Alternative Vote (AV) are both algorithms for determining local representation: they make no deliberate effort to make the output of a collection of constituencies proportional to the proportion of votes cast for a particular party across the country. The degree to which they give proportionality is dependent on the spatial distribution of voters for each party across the country and the locations in which electoral boundaries are drawn1. The current distribution of party support is not far off the point where it can give completely perverse results with the Liberal Democrats gaining the largest fraction of the popular vote and the fewest parliamentary seats and Labour gaining the smallest fraction of the popular vote and the largest number of parliamentary seats2.

The FPTP system acts to supress the formation of more than two political parties, this is known as Duverger’s law. You can see this in action in the UK, with the separation of the SDP from Labour in the early 1980’s, gaining a large fraction of the popular vote: approaching that of Labour, but nothing like the same number of seats3.

Best estimates for AV in a UK general election are that the Liberal Democrats will gain seats in a Westminster election and Labour and the Tories will lose some, it isn’t particularly clear who will lose most.

So moving on to the self-interest of parties:

The Liberal Democrats are in favour of AV because they will get more seats, this is OK because they will still have far fewer seats than their proportion of the vote should allow.

The Tories are against AV because they believe that they will lose seats to the Liberal Democrats for the same share of the vote, and that Labour-Liberal Democrat coalitions are more likely than Tory-Liberal Democrat coalitions. Wait! What?

Labour is split on AV, this is because some believe that Labour-Liberal Democrat coalitions are more likely than Tory-Liberal Democrat coalitions, and the Tories could be basically locked out of power for ever. Others in Labour, on the left of the party, believe that the Socialist utopia should be pure and that coalition is anathema and so oppose AV.

UKIP is in favour of AV because they believe that they will be first preference for a number of people who vote Tory tactically and second preference for a number of Tories. Their visibility will rise, even if it doesn’t lead to much increase in seats.

The Greens are in favour of AV because they believe they will pick up second preferences from Liberal Democrats and Labour.Their visibility will rise, even if it doesn’t lead to increased seats.

The BNP is against AV because it judges that it will not pick up second preferences from anyone. It decreases the likelihood of them gaining seats even if it increases the visibility of the party. The BNP is entirely visible already but for the wrong reasons.

Oddly those on either side of the debate are able to draw on arguments that match the self-interest of their parties. What is the non-aligned voter to make of this?

Footnotes

  1. Oxford is a nice example of this: across the two Oxford parliamentary seats (Oxford East and Oxford West and Abdingon) the number of votes for the three main parties are (LibDem: 41087, Tory: 33633, Lab: 27937. The two constituencies return a Labour and a Tory MP.
  2. Don’t believe me? Put Tory: 33.2%, Labour: 27.2%, LibDem: 27.7% Other: 11.9% into this BBC seat calculator. The actual result was Tory: 36.1%, Labour: 29.0%, LibDem: 23.0% Other: 11.9%
  3. The 1983 General Election. Vote share: Tory: 42.4% Labour: 27.6% SDP+Liberal Alliance: 25.4% Number of seats: Tory: 397 Labour: 209 SDP+Liberal Alliance: 23.
  4. Given 1-3, on what basis is it that we claim to live in a democracy?

Apr 11 2011

Yes to AV!

Alongside the local elections on the 5th May, we will all have an opportunity to vote in a referendum on voting reform*. The choice is between keeping the current system, First Past the Post (FPTP) or switching to the Alternative Vote (AV) system.

The Liberal Democrats use Single Transferrable Vote (STV) to elect their leaders. Labour uses straightforward AV. The Tories use a system to elect their leader which is substantially equivalent to AV: a ballot is taken with all candidates standing; if more than two candidates are standing then the last placed candidate is knocked-out and the ballot is repeated – this process is continued until only two candidates remain. In this two candidate election the candidate with most votes wins. The Tories could have used a straightforward FPTP system, but they didn’t: if they had then David Davies, not David Cameron, would have won the 2005 leadership election.

AV is substantially similar to this process of successive ballots but rather than a sequence of ballots, a single ballot is held with voters ranking candidates by preference. In common with the Tory system, the last candidate is eliminated after the first ballot but rather than return to the electorate for another round of voting the second preferences of the people who voted for the loser are inspected and votes redistributed accordingly. This process is repeated until one candidate has more than 50% of the votes.

The Tory leadership election is not identical to AV because the electorate can switch votes between rounds, whilst in an AV election the rankings are chosen and frozen at the time of the first (and only) ballot. With electorates of tens of thousands the Tory leadership system could not be used for parliamentary constituencies without substantially increased cost and time taken to conduct the election, I will assert that it would produce the same result as AV.

These political sophisticates have rejected FPTP as a method of choosing who represents them, why do so many of them not support the same for us?

AV will not bring great changes to our elections, the majority of constituencies would return the same MP under AV as they currently do under FPTP. The benefit of AV over FPTP is that tactical voting, where you attempt to encode your preferences with a single X by second guessing who everyone else will vote for, becomes largely irrelevant.

We are not being given a choice between FPTP and an ideal electoral system, we are not being asked whether AV is a perfect system for voting, we are being given a choice between FPTP and Alternative Vote. Personally I would prefer a system of proportional representation, but that isn’t on offer.

In the absence of a better choice I will vote “Yes to AV”!

*The BBC have apparently banned themselves from describing the choice of AV over FPTP as “reform”

Apr 09 2011

Book Review: The Chemist Who Lost His Head by Vivian Grey

Portrait_of_Antoine-Laurent_Lavoisier_and_his_wife

Following on from “The Measure of All Things” my interest in Antoine Lavoisier was roused, so I went off to get a biography: “The Chemist who lost his head: The Story of Antoine Laurent Lavoisier” by Vivian Grey. This turns out to be a slim volume for the younger reader, in fact my copy appears to arrive via the Jenks East Middle School in Tulsa. As a consequence I’ve read it’s 100 or so pages in under 24 hours – that said it seems to me a fine introduction.

Antoine Lavoisier lived 1743-1794. He came from a bourgeoisie family, the son of a lawyer, and originally training as a lawyer. Subsequently he took up an education in a range of sciences. As a young man, in 1768, he bought into the Ferme Générale which was to provide him with a good income but led to his demise during the French Revolution. The Ferme Générale was the system by which the French government collected tax, essentially outsourcing the process to a private company. Taxes were collected from the so-called “Third Estate”, those who were not landed gentry or clergy. Grey indicates that Lavoisier was a benign influence at the Ferme Generale, introducing a system of pensions for farmers and doing research into improved farming methods. Through the company he met his future wife, Marie Anne Pierrette Paulz, daughter to the director of the Ferme – Antoine and Marie married in 1771 when she was 14 and he 28.

Lavoisier started his scientific career with a geological survey of France, which he conducted as an assistant to Jean Etienne Guettard between 1763 and 1767. This work was to be terminated by the King, but was completed by Guettard with Antoine Grimoald Monnet although Lavoisier was not credited. There seems to be some parallel here with William Smith’s geological map of the UK produced in 1815.

Through his geological activities Lavoisier became familiar with the mineral gypsum, found in abundance around Paris. He undertook a detailed study of gypsum which sets the theme for his future chemical research: making careful measurements of the weight of material before and after heating or exposure to water. He discovered that gypsum is hydrated: when heated it gives off water, when the dehydrated powder (now called plaster of Paris) is re-hydrated it forms a hard plaster. He wrote this work up and presented it to the Académie des Sciences – the French equivalent of the Royal Society, on which I have written repeatedly.

He was to present several papers to the Académie before being elected a member of this very elite group at the age of twenty-five, half the age of the next youngest member. Once a member he contributed to many committees advising on things such as street lighting, fire hydrants and other areas of civic interest, the Académie was directly funded by the King and more explicitly tasked with advising the government than the Royal Society was. Lavoisier was also involved in the foundation of the new metric system of measurement, which was the subject of “The Measure of All Things”. Lavoisier became one of four commissioners of gunpowder – an important role at the time. During his life he would have had contact with Joseph Banks – a long term president of the Royal Society, and also Benjamin Franklin – scientist and also United States Ambassador to France.

From a purely scientific point of view Lavoisier is best known for his work in chemistry: his approach of stoichiometry – the precise measurement of the mass of reactants in chemical reactions led to his theory of combustion which ultimately replaced the phlogiston theory. It is this replacement of phlogiston theory with the idea of oxidization that forms the foundation of Kuhn’s “paradigm shift” idea, so Lavoisier has a lot to answer for!

The portrait of Antoine and Marie Laviosier at the top of the page is by Jacques-Louis David painted ca. 1788. It strikes me as quite an intimate portrait with Marie pressed against Antoine, looking directly at the viewer whilst her husband looks at her. Marie played a significant part in the work of Lavoisier, as well as recording experiments and drawing apparatus (something that takes good understanding to do well), and assisting with correspondence and translation  she was also responsible for publishing Mémoires de Chimie after his death. She was a skilled scientist in her own right. The equipment on the table and floor can be identified: on the floor is a portable hydrometer and a glass vessel for weighing gases. On the table are a mercury gasometer, and a glass vessel container mercury – likely illustrating the properties of oxygen and nitrogen in air.

Antoine Lavoisier was executed in 1794, for his part in the Ferme Générale. His execution is attributed, at least in part to the ire of Jean-Paul Marat, who Lavoisier had earlier blocked from membership of the Académie des Sciences. It seems Lavoisier had been warned by friends that his life was in danger but appeared to think his membership of the Académie des Sciences would protect him. Ironically Jacques-Louis David also painted “The Death of Marat”.

100 pages on Lavoisier was not enough for me, I’m going for “Lavoisier” by Jean-Pierre Poirier next – some fraction of which appears to be available online, but I’m going for a paper copy.

Apr 03 2011

Obsession

This is a short story about obsession: with a map, four books and some numbers.

My last blog post was on Ken Alder’s book “The Measure of All Things” on the surveying of the meridian across France, through Paris, in order to provide a definition for a new unit of measure, the metre, during the period of the French Revolution. Reading this book I noticed lots of place names being mentioned, and indeed the core of the whole process of surveying is turning up at places and measuring the angles to other places in a process of triangulation.

To me places imply maps, and whilst I was reading I popped a few of the places into Google Maps but this was unsatisfactory to me. Delambre and Mechain, the surveyors of the meridian, had been to many places. I wanted to see where they all were. Ken Alder has gone a little way towards this in providing a map: you can see it on his website but it’s an unsatisfying thing: very few of the places are named and you can’t zoom into it.

In my investigations for the last blog post, I discovered the full text of the report of the surveying mission, “Base du système métrique décimal”, was available online and flicking through it I found a table of all 115 triangles used in determining the meridian. So a plan is formed: enter the names of the stations forming the 115 triangles into a three column spreadsheet; determine the latitude and longitude of each of these stations using the Google Maps API; write these locations out into a KML file which can be viewed in Google Maps or Google Earth.

The problem is that place names are not unique and things have changed in the last 200 years. I have spent hours transcribing the tables and hunting down names of obscure places in rural France, hacking away with Python and loved every minute of it. Cassini’s earlier map of France is available online but the navigation is rather clumsy so I didn’t use it. Although now I come to writing this I see someone else has made a better job of it.

Beside three entries in the tables of triangles are the words: “Ce triangle est inutile” – “This triangle is useless”. Instantly I have a direct bond with Delambre, who wrote those words 200 years ago –  I know that feeling: in my loft is a sequence of about 20 lab books I used through my academic career and I know that besides an (unfortunately large) number of results the word “Bollocks!” is scrawled for very similar reasons.

The scheme with the the Google Maps API is that your program provides a place name “Chester, UK”, for example, and the API provides you with the latitude and longitude of the point requested. Sometimes this doesn’t work, either because there are several places with the same name or the placename is not in the database.

I did have a genuine Eureka moment: after several hours trying to find missing places on the map I had a bath and whilst there I had an idea: Google Earth supports overlay images on its maps. At the back of the “Base du système métrique décimal” there is a set of images showing where the stations are as a set of simple line diagrams. Surely I could overlay the images from Base onto Google Earth and find the missing stations? I didn’t leap straight from the bath, but I did stay up overlaying images onto maps deep into the night. It turns out the diagrams are not at all bad for finding missing stations. This manual fiddling to sort out errant stations is intellectually unsatisfying but some things it’s just quicker to do by hand!

You can see the results of my fiddling by loading this KML file into Google Earth, if you’re really keen this is a zip file containing the image overlays from “Base du système métrique décimal” – they match up pretty well given they are photocopies of diagrams subject to limitations in the original drawing and distortion by scanning.

What have I learned in this process?

  • I’ve learnt that although it’s possible to make dictionaries of dictionaries in Python it is not straightforward to pickle them.
  • I’ve enjoyed exploring the quiet corners of France on Google Maps
  • I’ve had a bit more practice using OneNote, Paint .Net, Python and Google Earth so when the next interesting thing comes along I’ll have a head start.
  • Handling French accents in Python is a bit beyond my wrangling skills.

You’ve hopefully learnt something of the immutable mind of a scientist!
View

 



Mar 31 2011

Book review: The Measure of All Things by Ken Alder

TheMeasureOfAllThings“The Measure of All Things“ by Ken Alder tells the story of Pierre Méchain and Jean Baptiste Joseph Delambre’s efforts to survey the line of constant longitude (or meridian) between Dunkerque and Barcelona through Paris, starting amidst the French Revolution in 1792.

The survey of the meridian was part of a scheme to introduce a new, unified system of measures. The idea was to fix the length of the new unit, the metre, as 1/10,000,000th of the distance between the North Pole and the equator on a meridian passing through Paris.

At the time France used an estimated 250,000 different measures across the country with each parish having it’s own (uncalibrated) weights and measures with different measures for different types of material i.e. a “yard” of cotton was different from a “yard” of silk, and different if you were buying wholesale or selling to end users. These measures had evolved over time to suit local needs, but acted to supress trade between communities. Most nations found themselves in a similar situation.

Although the process of measuring the meridian started under the ancien regime, it continued in revolutionary France as a scheme that united the country. The names associated with the scheme: Laplace, Legrendre, Lavoisier, Cassini, Condorcet, leading lights of the Academie des Sciences, are still well known to scientists today.

Such surveying measurements are made by triangulation, a strip of triangles is surveyed along the line of interest. This involves precisely measuring the angles between each each vertex of the triangles in succession: given the three angles of a triangle and the length of one side of the triangle the lengths of the other two sides can be calculated. It’s actually only necessary to measure the length of one side on one triangle on the ground. Once you’ve done that you can use the previously determined lengths for successive triangles. All of France had been surveyed under the direction of César-François Cassini in 1740-80, the meridian survey used a subset of these sites measured at higher precision thanks to the newly invented Borda repeating circle. As well as this triangulation survey a measure of latitude was made at points along the meridian by examining the stars.
The book captures well the feeling of experimental measurement: the obsession with getting things to match up via different routes; the sick feeling when you realise you’ve made a mistake perhaps never to be reversed; the frustration at staring at pages of scribbles trying to find the mistake; the pleasure in things adding up.

Méchain and Delambre split up to measure the meridian in two sections: Delambre taking the northern section from Dunkerque to Rodez and Méchain the section from Rodez to Barcelona. Méchain delayed endlessly throughout the project, trusting little measurement to his accompanying team. Early on in the process, at Barcelona, he believed he had made a terrible error in measurement, but was unable to check whilst Spain and France were at war. He was wracked by doubt for the following years, only handing over doctored notes with great reluctance at the very end of the project. He was to die not long after the initial measurements were completed, leaving his original notes for Delambre to sift through.

At the time the measurements were originally made the understanding of experimental uncertainty, precision and accuracy were poorly developed. Driven in part by the meridian project and similar survey work by Gauss in Germany, statistical methods for handling experimental error more rigorously were developed not long afterwards. I wrote a little about this back here. Satellite surveying methods show that the error in the measurement by Méchain and Delambre is equivalent to 0.2 millimetres in a metre or 0.02%.

In the end the Earth turns out not to be a great object on which to base a measurement system: although it’s pretty uniform it isn’t really uniform and this limits the accuracy of your units. The alternative proposed at the time was to base the metre on a pendulum: it was to have the length necessary to produce a pendulum of period 2 seconds. This is also ultimately based on properties of the Earth since the second was defined as a certain fraction of the day (the time the Earth takes to rotate on its axis) and the local gravity which varies slightly from place to place, as Maskelyne demonstrated.

Following the Revolution, France adopted, for a short time, a decimal system of time as well as metric units but these soon lapsed. However, the new metric units were taken up across the world over the following years – often this was during unification following war and upheaval.

The definition of the basic units used in science is still an active area. The definition of the metre has not relied on a unique physical object since 1960, rather it is defined by a process: the distance light travels in a small moment of time. However, the kilogram is still defined by a physical object but this may end soon with some exquisitely crafted silicon spheres.

I must admit to being a bit wary of this book in the first instance, how interesting can it be to measure the length of a line? However, it turns out I like to read history through the medium of science and the book provides an insight into France at the Revolution. Furthermore measuring the length of a line is interesting, or it is to a physicist like me.

Thanks to @beckyfh for recommending it!

Footnotes
1. The full-text of the three volume “Base du système métrique décimal” written by Delambre is available online. The back of the second volume contains summary tables of all the triangles and a diagram showing their locations.
2. The author’s website.
3. Some locations in Google Maps.