Archive for September, 2004

On Mathematical models of the recall vote and fraud, part VII: Hausmann and Rigobon, a wedge of black swans?

September 6, 2004

Yesterday, Sumate held a press conference which I did not mention because I simply did not understand what they had done in terms of proving or not the existence of fraud, this was based on a study by Ricardo Hausmann of Harvard University and Roberto Rigobon of MIT  (HR) which was made available (at least to me!) today. The study they did is quite technical, so I will not try to explain it in detail but only give you an idea of what they did. The report is entitled: Searching for a black swan: Analysis of the statistical evidence about electoral fraud in Venezuela.


Besides the technical details, the report repeats a number of issues which are important in understanding the possibility of fraud; it also adds some information which should be here for the record. According to HR these are the elements that lead to a presumption of fraud:


 


1-The opposition wanted a manual count from the beginning, but it was electronic.


2-There was no manual counting of the printed ballots, instead there was to be a “hot audit” of 1% of the ballot boxes which never took place. Only 78 boxes were counted, with the opposition present in the counting of 28.


3-International Observers were not allowed in the totalization room, neither was the opposition.


4-The voting machines had bidirectional communications. (My note: The Head of Smartmatic said this was not the case in his press conference the week after the vote).


5-Contrary to what was agreed on, the voting machines communicated with the servers before printing the results.


6-Exit polls disagree with the results. (I add: And those whose details have been made available agree with each other)


7-In the second audit the random selection of boxes was made using the software provided by the CNE.


 


Exit Polls


 


The report provides interesting data on them. For example:


 


Percentage of SI votes in Sumate’s exit poll                                                        59.5%


Percentage of SI’s according to CNE in centers where Sumate did exit polls     42.9%


Percentage of SI votes in PJ’s exit poll                                                                 62.6%


Percentage of Si’s according to CNE in centers where PJ did exit polls              42.9%


 


The idea is that people always dismiss exit polls suggesting they are not done in the right place. Well, given that the SI received at the national level 40.63%, the difference is not that significant in the final results where the exit polls were performed.


 


Caps or coincidences


 


They test statistically for the caps and conclude that if there was fraud it was not via imposing caps on the maximum number of votes per machine. For quite a while I have referred to the caps as coincidences, believing they may be the consequence rather than how a fraud may be perpetrated. This would agree with that.


 


Detection of statistical fraud


 


What HR did was to look how to measure the intention of vote. To do that, they looked at two independent measures of the intention of vote: The exit poll results and the signatures from the Reafirmazo process. The idea is that each of these two represents real data, distinct from the actual vote, on vote intention. They then do a regression between signatures per center and the actual vote at those centers and the same regression between exit polls and the actual vote at the centers. In a regression you calculate the line or equation that best fits all of the points of the data you have, i. e. in the case of the exit polls what is the line that best fits the results announced by the CNE at those same centers.


 


When the above two regressions are done, there are errors, that is differences between the line and the points. But the sources of these errors are independents for the two processes. The only way in which they could be correlated (similar) is if the error has a common source, in this case fraud is the only possibility of “correlation” between the two. Well, the mathematical comparison of the errors of the regression yielded that there was a correlation of 0.24, where two things that do exactly the same have correlation 1 and two that have nothing to do with each other have correlation zero. To put it in a simple way: In voting centers where the signatures predicted a higher number of Si’s than the actual vote recorded, the exit polls also predicted a higher number of final votes.


 


Given that this correlation is simply too high and can not be explained away, they concluded that the only thing in common the two processes may have, is fraud.


 


The audit


 


Using statistical theory HR calculated the possibility that some of the voting centers had their votes manipulated and other did not. What they did was to compare those centers that were audited with those that were not audited. If those audited came from the “same” sample there should be no difference as the sample should be random. The result is quite remarkable: the results for the centers that were audited generated 10% more SI votes than those that were not audited. The probability that this was coincidental is less than 1%. Thus, the rather strong conclusion is that the centers were not chosen at random!


 


HR conclude by saying that in statistics it is impossible to confirm a hypothesis, but you can reject one. They then quote Popper who said that observing 1000 white swans did not prove all swans were white, but if you see a black one, you can reject that hypothesis. To HR their results are that they found a black swan, therefore, the hypothesis that there was a fraud is consistent with their results and thus, they can not reject it.


 


Well, my feeling is that with Elio’s work, Bruno’s and Raquel’s and some more that are soon to be revealed, what we have is a wedge of black swans getting together and forming! Someone should be getting worried, both here and abroad!


 


Join a discussion of this post

A summary of problems with recall vote

September 5, 2004

A very brief summary of what we know:


-Exit polls: Very low probability of sample being taken from those final results according to Sanso and Prado, using three different exit polls.


-Hot Audit: Incomplete, opposition present in only 27, in those Si won handily. Most never completed.


-Cold Audit: Random Sample being questioned, may not have been that random. CD not allowed to choose boxes.


-Coincidences: Very low probability of happening, 1 to 3 in 1000 according to Prof. Taylor.


Quick Poll: Only thing that there is agreement it was OK by all parties.


What do you think? Paranoia? Just coincidences? De que vuelan, vuelan?


(In Spanish there is a saying: I don’t believe in witches, but that they fly, they fly)

A summary of problems with recall vote

September 5, 2004

A very brief summary of what we know:


-Exit polls: Very low probability of sample being taken from those final results according to Sanso and Prado, using three different exit polls.


-Hot Audit: Incomplete, opposition present in only 27, in those Si won handily. Most never completed.


-Cold Audit: Random Sample being questioned, may not have been that random. CD not allowed to choose boxes.


-Coincidences: Very low probability of happening, 1 to 3 in 1000 according to Prof. Taylor.


Quick Poll: Only thing that there is agreement it was OK by all parties.


What do you think? Paranoia? Just coincidences? De que vuelan, vuelan?


(In Spanish there is a saying: I don’t believe in witches, but that they fly, they fly)

Letter to Prof. Johnathan Taylor

September 5, 2004

I just sent this letter to Prof. Johnathan Taylor of Stanford University


(Use links in text, line links don’t work)


Dear Prof. Taylor:

On Aug. 16th. Venezuelan opposition analysts began charging that there
were some surprising numerical coincidences in the number of SI votes
within voting centers in Venezuela. The Carter Center and the
Electoral Board said on the 18th. that there were only 402 and this
was reasonable.

But this was not what the opposition was charging, the 402 repetitions
were across the “mesas” (tables) and not across the machines. Thus,
apparently the Carter Center had consulted on the  wrong problem.

In my blog, I explained the difference on Aug. 18th.:

http://blogs.salon.com/0001330/2004/08/18.html#a1702

pointing out that a center may have a number of mesas, but that each
mesa may have a variable number of “cuadernos”. In centers with
electronic voting, each cuaderno is equals to one machine. Thus, the
lowest equivalent unit is the cuaderno (machine) not the mesa.

On the 22nd. I reiterated the issue:

http://blogs.salon.com/0001330/2004/08/22.html

pointing out that the 402  SI coincidences at the mesa level, became
805 coincidences at the center level with 1879 machines involved in
these coincidences.

Elio Valladares took a first stab at the mesa problem:

http://blogs.salon.com/0001330/2004/09/01.html#a1732

reaching conclusions that you now agree with.

However, it was not until yesterday that Elio solved the problem in
what I believe is the correct way, he did his simulations at the
cuaderno (machine) level and from there calculated the coincidences
for the SI vote at the mesa level. His results (attached) indicate

<!– D(["mb","that the probability of the number of coincidences reported is about 1\
in 10,000 when the problem is considered at the machine (cuaderno)\
level. Certainly a worrisome result given what is at stake.\
\
While no mathematical study will prove that there was fraud, it\
certainly seems suspicious that these coincidences apparently have\
such low probability, that a statistical study of exit polls by Prof.\
Sanso and Prof. Prado of the University of California at Santa Cruz:\
\
\http://blogs.salon.com/0001330\/2004/08/26.html#a1720\\
\
also finds very little probability of those exit polls matching the\
vote at each voting center and that the live audit of comparing 199\
ballot boxes the night of the vote was never completed.\
\
The Carter Center, based on your earlier conclusion disregarded the\
problem of coincidences. I believe it is only fair that you calculate\
the same problem Elio Valladares calculated at the machine level and\
using your conclusions help decide whether the Carter Center and the\
OAS should or should not reopen the case for fraud in the Venezuelan\
recall vote.\
\
Respectfully.\
“,1] ); //–>
that the probability of the number of coincidences reported is about 1
in 10,000 when the problem is considered at the machine (cuaderno)
level. Certainly a worrisome result given what is at stake.

While no mathematical study will prove that there was fraud, it
certainly seems suspicious that these coincidences apparently have
such low probability, that a statistical study of exit polls by Prof.
Sanso and Prof. Prado of the University of California at Santa Cruz:

http://blogs.salon.com/0001330/2004/08/26.html#a1720

also finds very little probability of those exit polls matching the
vote at each voting center and that the live audit of comparing 199
ballot boxes the night of the vote was never completed.

The Carter Center, based on your earlier conclusion disregarded the
problem of coincidences. I believe it is only fair that you calculate
the same problem Elio Valladares calculated at the machine level and
using your conclusions help decide whether the Carter Center and the
OAS should or should not reopen the case for fraud in the Venezuelan
recall vote.

Respectfully.

Carter Center trying to look good, defends results from Rubin now

September 5, 2004

I guess I was not the only one paying attention, here JorgeRodriguez says they talked to Prof. Taylor and he saw the same text I posted, but now Taylor is being pressured. Meanwhile Jennifer MCoy continues skirting the issue and now talks about other experts, without realizing that they have not even solved the correct problem. They even issue a new report and now side with Rubin’s data. This is now getting interesting as I added in the note below, Elio Valldares has solved a more complete problem and he gets a probability of one in 10,000 for the coincidences observed. Tulio Alvarez, the lawyer preparing the case, now says the Carter Center played the role of useful idiots. The attempts today by the Carter Center to me are more irresponsible than idiotic.


I think both Taylor and Rubin, should work on the real problem at the machine level to calculate what Elio Valladares did and shut up the Carter Center for once and for all. Enough!

Carter Center trying to look good, defends results from Rubin now

September 5, 2004

I guess I was not the only one paying attention, here JorgeRodriguez says they talked to Prof. Taylor and he saw the same text I posted, but now Taylor is being pressured. Meanwhile Jennifer MCoy continues skirting the issue and now talks about other experts, without realizing that they have not even solved the correct problem. They even issue a new report and now side with Rubin’s data. This is now getting interesting as I added in the note below, Elio Valldares has solved a more complete problem and he gets a probability of one in 10,000 for the coincidences observed. Tulio Alvarez, the lawyer preparing the case, now says the Carter Center played the role of useful idiots. The attempts today by the Carter Center to me are more irresponsible than idiotic.


I think both Taylor and Rubin, should work on the real problem at the machine level to calculate what Elio Valladares did and shut up the Carter Center for once and for all. Enough!

Three species, two local, one from Asia

September 5, 2004


I have been paying too much attention to politics and little to the orchid part of my blog, I apologize. But here are three real treats. Above left: Venezuelan Cattleya Percivaliana, a very stinky flower, but look at the darkness of that lip. On the right a Cattleya Lueddemaniana cross Clint McCade x Raga from Armando Mantellini, also a Venezuelan species, very fragant. Below, from Asia a Cyrropetalum Amabile, which I can’t find in my book so I can not tell you where its from. But notice how delicate it is.


On Mathematical models of the recall vote and fraud, part V: Prof. Taylor posts correction, changing Carter Center conclusions

September 5, 2004

A reader, Mercedes Rosas,  has pointed out in the comments below to a correction in the webpage by Prof. Jonathan Taylor of Stanford University and an e-mail from Prof. Taylor to her, on the results of the recall vote in which he says he made an error earlier and corrects hs results. Prof. Taylor’s work was used by the Carter Center to “show” that the number of “Si” coincidences in the mesa (table) votes was reasonable. This result was widely used and quoted by the international press as part for the “evidence” that there was no evidence of fraud in the recall vote.


As I have reported elsewhere, Elio Valladares got quite a different result, suggesting that the probability was not that “reasonable”, in fact Elio obtained that it was small, if not miniscule. Now Prof. Taylor has corrected his work on his web page and I would like to quote him so that there is no misinterpretation of what he says or not:


 


“ It seems that an expected number of ties between 345 and 350 is reasonable, as it came out from many different models. Using the Poisson assumption to estimate the standard error, it seems then that the probability of observing 402 or more ties for SI is between 1 and 3 in 1000. While this probability is small, I do not feel that it should be interpreted as overwhelming evidence of fraud.”


 


Yes, is not overwhelming, but we have gone from reasonable to small, but it was the reasonable that led the Carter Center to its conclusion. What would they say now?. By the way, the CNE also used this result by Prof. Taylor to say that the Si vote coincidences were irrelevant.


 


Prof. Taylor has acted with the integrity characteristic of scientists, I wonder if the Carter Center will post a clarification to their conclusions, but doubt it. I sure hope Prof. Taylor will now calculate the coincidences at the machine level. I believe in that case he will find that the probability is even lower, if not impossible!!! That should have been the case that the Carter Center should have had him study to begin with!


 


Note added: I have now received a new study by Elio Valladares in which, if I understand correctly, he simulates the vote at the level of the cuadernos (each cuaderno is a machine in centers with electronic voting) rather than at the mesa level. He then calculates then the probabilities at the mesa level using the results from the simulation of the cuadernos. His conclusion from this is that the number of observed SI vote coincidences should be 1 in 10,000, which I think even Prof. Taylor would consider we are getting into the realm of the “overwhelming evidence of fraud”


 


Second note added: Prof. Taylor has now removed the word overwhelming from his conclusions. I wish that rather than worry about words, they would work on the real problem at the machine level.

On Mathematical models of the recall vote and fraud, part V: Prof. Taylor posts correction, changing Carter Center conclusions

September 5, 2004

A reader, Mercedes Rosas,  has pointed out in the comments below to a correction in the webpage by Prof. Jonathan Taylor of Stanford University and an e-mail from Prof. Taylor to her, on the results of the recall vote in which he says he made an error earlier and corrects hs results. Prof. Taylor’s work was used by the Carter Center to “show” that the number of “Si” coincidences in the mesa (table) votes was reasonable. This result was widely used and quoted by the international press as part for the “evidence” that there was no evidence of fraud in the recall vote.


As I have reported elsewhere, Elio Valladares got quite a different result, suggesting that the probability was not that “reasonable”, in fact Elio obtained that it was small, if not miniscule. Now Prof. Taylor has corrected his work on his web page and I would like to quote him so that there is no misinterpretation of what he says or not:


 


“ It seems that an expected number of ties between 345 and 350 is reasonable, as it came out from many different models. Using the Poisson assumption to estimate the standard error, it seems then that the probability of observing 402 or more ties for SI is between 1 and 3 in 1000. While this probability is small, I do not feel that it should be interpreted as overwhelming evidence of fraud.”


 


Yes, is not overwhelming, but we have gone from reasonable to small, but it was the reasonable that led the Carter Center to its conclusion. What would they say now?. By the way, the CNE also used this result by Prof. Taylor to say that the Si vote coincidences were irrelevant.


 


Prof. Taylor has acted with the integrity characteristic of scientists, I wonder if the Carter Center will post a clarification to their conclusions, but doubt it. I sure hope Prof. Taylor will now calculate the coincidences at the machine level. I believe in that case he will find that the probability is even lower, if not impossible!!! That should have been the case that the Carter Center should have had him study to begin with!


 


Note added: I have now received a new study by Elio Valladares in which, if I understand correctly, he simulates the vote at the level of the cuadernos (each cuaderno is a machine in centers with electronic voting) rather than at the mesa level. He then calculates then the probabilities at the mesa level using the results from the simulation of the cuadernos. His conclusion from this is that the number of observed SI vote coincidences should be 1 in 10,000, which I think even Prof. Taylor would consider we are getting into the realm of the “overwhelming evidence of fraud”


 


Second note added: Prof. Taylor has now removed the word overwhelming from his conclusions. I wish that rather than worry about words, they would work on the real problem at the machine level.

The untouchable pensions

September 4, 2004

This week two things happened that reminded me of one of the most perverse things that goes on in this country and nothing ever gets done about it: Government pensions. The two things that happened were the resignation of Minister Hector Navarro from the Ministry of Higher Education and the issuing of new pension rules at the Venezuelan Central Bank.


Navarro, who has been a Minister from day one of the Chavez administration, quit his position in order to go back to his duties at Universidad Central de Venezuela and retire in one and a half years. Navarro is in his late forties or early fifties and will take advantage of the generous pensions in Venezuelan Universities which allow you to retire after 25 (twenty five) years at full salary and benefits, without ever contributing to a pension fund. Moreover, the system is such that when the salary of Professors is increased, retired Professors get the increase too. Additionally, if you die, the same benefits are transferred over to your widow until her death.


 


Similarly, the Central Bank issued new ¨tougher¨ rules on pensions from that institution. by which men wanting to retire will now need 20 years of service if they are 60 years old, 20 if you are 55 years old or 35 years of service. For women, they can retire after 20 years of service if they are 55 years old. All of these pensions are automatically adjusted if the person holding your last position receives a salary increase. Thus, all former Presidents of the Central Bank who have retired, and there are a few around receive the same pension, all without ever having contributed to a pension fund.


 


This extremely absurd system has been in place for a long time. No country, however rich can sustain a pension system like this one. There have been two attempts to change it; one was changed at the last minute. The second one took place during Caldera’s last year, led by Tal Cual Editor´s Teodoro Petkoff and was supposed to take effect on the year 2000. That bill established both Government and private pension funds which would be by contribution only. Additionally, it established uniform criteria for retirement, either 65 years of age or 35 years of service. In addition to providing a healthy pension system, it wouldprovide a pool of savings that could invest in Government bonds, solving two problems at once. The perversity had been supposedly eliminated from the system; much like Lula did in Brazil in his first year in power.


 


When Chavez got to power he named a commission to study the new law and gave it six months to make changes. Then he extended it six months. He gave them an additional six months and, unfortunately, that was the last we heard of the issue.


 


The commission made a big deal out of the fact that the laws allowed the banks to get into the pension fund business. The way I understand it however, was that most of the members of the Commission were either revolutionary academics that felt their future pensions were threatened by the Bill, or MVR or PPT politicians who saw their extremely generous Assembly pensions in danger.


 


The result was typical Venezuelan: do nothing. Unfortunately, only a few will continue to benefit from this indecision, in a manner which I find both obscene and perverse. But this is not a political issue, for either side.