Sunday, August 7, 2016

Bad Science behind introduction of genetically modified Zika mosquitos to control their population

Zika is spreading a little bit outside Brazil and Colombia, and a company called Oxitec is proposing a solution. In all likelihood they are twisting their data to fit their needs-to make it look like the mosquitoes they introduce really cause a decrease in the overall mosquito population.

News stories Here and Here for a sum-up of what they are proposing.

"Trials of the modified mosquitoes in Brazil, Panama and the Cayman Islands suggest they reduced local populations of Aedes aegypti mosquitoes by more than 90 per cent," Oxitec says.

Here's the problem from an evolutionary point of view-just because you have created this male Aedes aegypti mosquito which transmits the gene so that  the offspring are killed before they reach adulthood doesn't mean that the females will mate with them. Even if the sexual selection be random, you will just eliminate the offspring of these males; but the other males, who are a large part of the population, will continue producing offspring. This is the best case scenario.

Sexual selection is not random-it is not like that females will mate with any mosquito-and if the mosquito population realize that the offspring of these genetically modified males are not reaching adulthood, they will probably weed them out by sexual selection even faster. Sexual selection by females will accelerate de demise of these traits.

From what Darwin explained in his Domestication of plants and animals and a little bit in the Origin of Species, it is clear that introducing new strains in a plant or animal is the easy part, the hard part is to make sure that their offspring survive the selection pressures of the others who are the more "stable" varieties. In his words, hybrids are easy to create-but will tend to revert to the stable varieties after a few generation, even if they can reproduce. Hybrids most likely will not even reproduce-and the reason was unclear to him-but the evidence is very strong that hybrids are difficult to breed, and even if they do breed, even more difficult is to ensure that their offspring survive and don't revert back to the parent varieties used to create the hybrid.

This thing about Zika males is very similar-and my bet is that introduction of these males has no effect whatsoever on the mosquito population of Zika.

Regarding the data from Brazil, Panama and Cayman Island-I  think the data has been fudged to give them what they want to prove. And doing it in a lab setting may have nothing to do with how this turns out in real life-with loads of other selection pressures on the mosquitoes, both from within and outside their species. This is similar to the myth of antibiotic resistance in many ways.

-Sanjay


Thursday, March 10, 2016

The foolishness of inflation measurements

A lot of garbage statistics is used to collect inflation data and to calculate stuff like CPI (Consumer price index). Your mortgage and other interest rates and sometimes your rent are adjusted to this number; and this statistical trickery of taking data to find out the value of money and how it varies over time has a bearing on your everyday life.

Can you give a precise value for money (dollars) by measuring the value of all other things the way the Index with the inflation basket does? I don't think so.  Here are the problems with this measurement:

1. It does not consider the statistical deviation in prices. Whenever an inflation data is published, I would like to know the standard deviation of the data. No mention is made; to hide the fact that the prices vary all the time! For the basket used to measure this data, what is the standard deviation of the prices?   The Index covers prices consumers pay for services from medical visits to airline fares, movie tickets and rents-all kinds of variable things, and you just can't add the means and come up with a value without talking about the variability or standard deviation of these things!

2. The choice of basket is arbitrary, and even if the data for the basket was statistically reliable, one can't say that the basket can be used to measure the general value of money over all things for all human beings (thousands of things and millions of human beings consuming them in different ways). It is a measure of money for that basket only, and any conclusions about the general spending habits of people in so many other ways they spend money from that basket is outright silly. The inflation data, strictly speaking, is valid just for that basket.

Any changes in the basket composition will give you altogether different values of inflation (which shows there's nothing real behind the data-what you are measuring is all noise, or in Nassim Taleb's terms-randomness).

3. Measuring the value of a basket in money terms, or a bunch of items in money terms, does not give you the value of money. The demand of money varies just like of other things (potatoes, electricity, whatever) and you cannot just average it out over a bunch of things and come up with "one value" of money, as a CPI calcuation does. The natural variation of prices of everything, and of money (cash) in itself, is not considered at all.  It also assumes that the reason the value of money is what it is is because of increase or decrease in supply of money; and does not consider that the demand of money, just like of any other commodity, is itself variable.

To explain this further-let's say we started measuring things in potatoes, and we could control the production of potatoes so that every year we would increase the potato supply by 2%. Can this be captured by measuring everything else in potatoes and coming up with something like "the supply of potatoes increased 2% in 1 year"? I believe it is impossible. With all things valued in potatoes, and because their value is itself very variable depending on the supply and demand, you will end up with a very noisy idea of the value of things in terms of potatoes. It is very unlikely that you will hit the mark of 2%. So even in a controlled enviroment, when you simply increase the supply of potatoes by 2% in a year, you will not be able to come up with the exact value by your statistical data taking of market prices. The same holds if you measure it in dollars or pesos.

4. It also assumes that the sellers of the goods run their businesses at constant profit percentage. In practice, businesses play with prices all the time, and often times will lower profit margins to get more volume. Such a strategy is not considered by inflation measurement fanatics-who assume that all variation in price is because of the variation in supply of money.

The basic idea of measuring things to get the value of money is not bad-you can get an idea, a very rough idea about inflation, if EVERYTHING in your basket goes up in price by a significant amount (at least 10%). This happens in Argentina and Venezuela, for example. Then you are able to see inflation-but even then to give an exact number to it like 20% per year or 50% per year is foolish. For small variation in prices, less than 5%, you cannot conclude that the price of things increased because you printed more money, or because of simply that the demand of money went down in relation to other things, etc.

If there was something real in measuring the value of money using things in the inflation basket-ALL items would go up with a very similar amount e.g. 5%. Then you can say with confidence that it is the price of money which is changing and it is not the statistical variation in it which you are capturing.

In effect, there are a lot of holes in the basket measurement of inflation. Any number which is less than 5% and is quoted as inflation is but noise-and they are careful to hide the noise by not publishing the standard deviation of data.

Other holes in the measurement of inflation: a) they invented something called "core inflation" to remove the volatile parts of the inflation basket, food and energy. A real statistician never discards any data, here it is being discarded on purpose to remove the deviations and noise in the data, to make the inflation numbers "smooth" and b) a small change in the composition of the inflation basket will lead to an entirely different number for inflation. If the real value of money was being measured, a change in just the composition of the inflation basket should make no difference.

Inflation measurements which are increasing steadily at say 2 or 4% per year are in reality a clever way of defrauding the persons who borrow-who almost always see their interest payment go up with time, because they measure the index in a peculiar way to make it increase slightly almost every year. The noise of the measurements is removed carefully to always come up with a slightly positive number  between 0% and 5%, to give the banks a license to increase interest payments on the borrowers. Or rent payments, which are also adjusted to inflation in most big cities. The inflation data publishers meet the needs of the market well-the massage the data to come up with a number of between 0 and 5%, and get to keep their jobs. But the real value of all this data is zero, for the reasons mentioned above.

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The futility of inflation measurements is best illustrated by countries like Panama and Ecuador, which use the US dollar as their currency. Since they have no influence or control over how US dollars, a foreign currency there, is valued, or is brought into their country, their inflation measurements are nothing but noise-in the sense that there can't be regular pattern to it. Amazingly, they do have inflation measurement departments...where dozens of statisticians and bureaucrats are employed to come up with this data. Link for Panama here   and Here for Ecuador. Since they can't do anything if the inflation is high or low, why measure it at all!

In Ecuador, the reported annual cumulative inflation was 3.38% in 2015, and 3.67% in 2014. The geniuses in Ecuador and Panama who are reporting these numbers, massage the data to make it look like a nice number, instead of saying it is statistical noise. They publish this number to keep the banking community and financial guys happy. As long as it is between 0 and 5%, everyone is happy. Data which will make it go beyond these is readily discarded.

Digression 1-As a general comment, I think most people, including Scientists, will make up or polish data to prove what they want to prove-because their jobs, their funding, etc. depends on it. In the end, for most people, it is just a job; and a bit of data jugglery is a part of their job, just as it is for people who work in Sales and Marketing-who will make up data to sell their products. Not more than 5% will publish the data as it is, and agree that it might just be noise (and this is in all walks of life, not just Economics, Medicine and Global Warming; subjects I have covered in this blog to show you how a lot of what you see is noise disguised or polished as data).

Digression 2-As I grow older, I realize that a lot of data we have around is is just noise, and a large amount of foolishness of humanity is to confuse this random data as relevant. This is how stuff like the existence of God and astrology was born. Even though Science has advanced greatly in the times since we invented the idea of God and planetary movement affecting our daily lives, I still find that a lot of humanity still confuses noise with data. Wherever people see patterns, I generally see noise. And as Nassim Taleb said so well in one of his books-good data shouts at you, you don't need to look for it or justify it by long arguments.
 

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The most ridiculous use of inflation data is by utilities  (electricity, telecom companies, etc.) and essential services companies. Utilities use this data to justify increasing rates. They say that because of inflation, they be allowed to raise rates. Since their own products form a part of the basket of things used to measure inflation, they basically go into a feedback loop-the basic necessities companies raise rates because of inflation data, and since the raise rates, next year inflation data shows even more inflation, and they raise rates even more. Imagine if every product or service in the inflation basket started raising rates, the next year's inflation would go through the roof! Here in Chile where I live, this is why gas and electricity prices are the highest in the Americas (North and South)..and the Government lets these utility companies increase rates , who use the excuse of higher inflation.

Here's what Smith said about increase of paper money possibly causing inflation (which seemed to be a theory in 1760 as much as it now!) in Book 2 of the Wealth of Nations, chapter on "Money Considered as a particular Branch of the General Stock of the Society"

"The increase of paper money, it has been said, by augmenting the quantity, and consequently diminishing the value of the whole currency, necessarily augments the money price of commodities. But as the quantity of gold and silver, which is taken from the currency, is always equal to the quantity of paper which is added to it, paper money does not necessarily increase the quantity of the whole currency. From the beginning of the last century to the present time, provisions never were cheaper in Scotland than in 1759, though, from the circulation of ten and five shilling bank notes, there was then more paper money in the country than at present. The proportion between the price of provisions in Scotland and that in England is the same now as before the great multiplication of banking companies in Scotland. Corn is, upon most occasions, fully as cheap in England as in France; though there is a great deal of paper money in England, and scarce any in France. In 1751 and in 1752, when Mr. Hume published his Political Discourses,*36 and soon after the great multiplication of paper money in Scotland, there was a very sensible rise in the price of provisions, owing, probably, to the badness of the seasons, and not to the multiplication of paper money."

Related post: Central banks have no influence in jobs creation, unemployment or real interest rates. Here's the post explaining this.

-Sanjay

Saturday, January 23, 2016

Understanding evolution-zebra article today

Some biologists today published a study on why they think zebra stripes are not for camouflage, etc. They do not seem to understand evolution quite right.

The winner in evolution transmits all their characteristics to the offspring. But  you can't say that the characteristic (e.g. stripes) was the cause of the individual being a winner.

A particular human being might be a survivor in a difficult situation because of their excellent intelligence. They may have a mole on their right chin, or have a hairy back, etc. All these characteristics will be passed on to their progeny; but it is not because of their hairy back or the mole on their right chin that they are a winner.

Or instead of intelligence, it might be just luck; maybe the individual just hid in a cave while the rest of the pack was eaten by a predator. Since this individual now reproduces, all his characteristics will be transmitted to his offspring.
This can be extended to all animals, I chose human being as an example animal, that's all.

The characteristics you see in a species like a zebra are just that; they are not there because somehow that characteristic lead the species to win out.

Even for sexual selection this is the same. The characteristic is not a cause of victory; it is a by product of already being victorious.

The same intelligent human being might be able to get more mates; but the females are not selecting the individual for their mole on the right chin or his hairy back.

This is a common problem I see in evolution related publications; essentially they do not get the causality right. The causes of why an individual survives are not known; the characteristics you see in an individual are the effects of them being winners.

Sanjay



Friday, December 25, 2015

Fools in Medicine

The issue of removing life-support to brain dead individuals comes up in the news quite often. The families normally want to give more time; but the expert doctors want to turn the thing off, probably to save costs, and let the patient die.

‘Brain dead’ son enjoys Xmas after dad armed with gun refuses to let medics end his life'

This is a major problem when medicine becomes a know-it-all cult, as it is in the US. The medics will not accept their own mistakes; and this story which fortunately has a happy ending is often times not even out in the press; because the medics are able to sell their "expert opinion" to the public. Often this is with social pressure-several of them will be together when taking this decision; so the family members think that they have really some knowledge here. Unfortunately, they are being lied too with group pressure.

Keep this in mind when someone goes into coma next time, and if need be, move them to a new country rather than a country where medics have more control over a patient than their own family members.

Sanjay

Wednesday, December 23, 2015

Probability fudging-drug companies with too many vaccinations, airplanes safer than cars

In this post I cover some examples of probability fudging which goes on around us daily. The basic tenet of this post is:
When probabilities of two things are low (less than 1%), the comparison between these two things loses confidence...it is a property of statistical distributions. If something is very rare, and something else is very very rare, it is difficult to compare them. You don't have much confidence in drawing conclusions.

HPV and rare disease Vaccinations

There is a lot of talk about Human Papillomavirus (HPV) vaccinations. Kids, especially girls, between the age of 10 to 15 years are recommended to get this vaccine. Let us look at the data, published by CDC here.

There are 79 Millions Americans (total population of about 300 Million) affected with HPV. There are 12 Million cases of new infections per year. Cancers attributed to HPV are 27000, of which 18000 are girls, the rest of 9000 being boys.

Since 1 in 4 Americans has the virus already, and 12 million get it every year, the virus itself can't be that bad. This is a classic case of measuring too much-if common bacteria presented in the mouth are measured, surefly 1 in 4 have some particular "infection"...most Americans get on with their lives just fine, and HPV infection, even if they don't know about it, doesn't seem to be a big deal in everyday life. From this data, it is more common than the common cold virus-and you begin to wonder how (and why) they collected this data at the first place. But let's trust the data for a moment anyway.

The cases where you have severe effects (cancers) are interesting to us, 27000. It is a large number, but looking at the overall population of HPV infected people (79 Million), it is a very small percentage, about 0.0034%.   Only 3 in 10000 people are getting cancers attributable to HPV.

The pharma companies say we can eliminate this tiny percentage of people getting cancers by injecting them with the HPV vaccine. The side effects of thee vaccine appear on the same page: Out of 67 million doses of vaccine, 25000 people reported some side effects, and 2000 of these were serious. The serious side effects are about 0.00025%, or about 0.25 in 10000. We must remember that many people may not report a problem even if their child has some side effects, so this number 25000 is likely to go up.

At first instance, it will look like the benefit of the vaccine, eliminating 3 in 10000 cancers, is about 10 times better than the serious side effects of the vaccine (0.25 in 10000). But these are very small percentages, do we have good reliability of such measurements? No. The confidence level at these probabilities is very low, and a vaccine needs to be at least a 100 times effective (than non vaccine) for it to be not drowned in statistical error.

If the disease is rare, like this HPV-cancer, does it make sense to vaccinate at all? Obviously what's rare and not rare is subjective, but to me, a disease which will going to happen to 3 in 10000 is quite rare, and we should not hurry to vaccinate kids against it. Couple that with the problem with this specific case where there's no clear indication that the HPV is causing the cancer (they are confusing correlation with causality, and assuming that the HPV vaccine with prevent cancers 30 years from now, which is very speculative an assumption) and you see that HPV should not be a mandatory vaccine.

When probabilities are very low, the right distribution to look at is the 1-x distribution. That is the statistical trickery these guys are doing to convince us of the wonderful effects of the vaccine. If x is small, less than 0.1% (1 in 1000), you must evaluate the risk of intervention causing more damage then the disease itself. Unless you have clear data that this does not happen, don't put vaccines (or other procedures)

Let us look at the 1-x distribution of the same data.

99.9964% will not develop a cancer related to HPV if they are not vaccinated.
99.99975% will develop a serious side effect if given a vaccine for HPV.

Everybody in their right mind can see that these are comparable numbers, and we do not need to vaccinate kids against HPV, because the risk of side effects is the in the same ball park as the benefit of taking the vaccine!

By focusing on the "x" distribution, the data is magnified; but in reality, the real distribution of interest is the 1-x, which is a stable distribution, and doesn't change much by vaccinating our children.

To make this more clear, let us look at other examples of daily life, where the 1-x distribution should be looked at, not the distribution of x.
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Airplane and Car driving safety

Airplanes are safe, driving in cars is safe. Most people know this, and will take a plane or car ride from a place to another without thinking about safety-they will only worry about costs and the conveniences and inconveniences when comparing the two. However, you have all sorts of bad statisticians comparing airplane safety to car safety, and concluding that airplanes are safer (or unsafer) than driving. The error there is that the 1-x is the real distribution of interest: the probability of survival. That is maybe 99.95% over 10 years of car driving  to 99.99% for plane riding, and those two are similar, dont you think? One thing is 99.99% safe, the other is 99.95% safe...we can agree that they are both quite safe. Noone thought that planes are significantly safer or unsafer than cars. Both are safe, the 1-x is the real distribution.

When the benefits are doubtful, as is the case for HPV vaccines (that's why they are banned in Europe, a continent not exactly stupid), it gets even worse; you are putting unnecessary risk for these kids in vaccinating them.

But from statistics alone you can see that pharma companies are comparing the wrong distribution to sell their drugs.

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