Corona Virus infection’s growth is not “exponential”

Yesterday night, Roberto Speranza, the Italian Health Minister, said to TG4 (the news programme of a National broadcaster) that the Coronavirus spreading in Italy is – or it has been -? “exponential”. As a matter of fact, this is not correct, as “exponential” has a specific mathematical meaning that does not match with the data provided by the Italian Government itself. Moreover, talking about “exponential growth” without indicating the exponent and specifying whether it is whole or fractional, does not allow the listener to understand what is the real “steepness” of the curve to which we are referring. Finally, at most, we can speak of an exponential trend in relation to a stretch of the curve, certainly not in relation to the curve itself. Unlike a mathematical function, in fact, the data on contagion are conditioned by variables? that vary (how many probes I did yesterday, how many I do today and how many I will do tomorrow, on which population I perform the analysis etc. etc.). In other words, the trend of the contagion curves (net of all the questions about the composition of the sample) has a (limited) descriptive capacity of the past, but it can hardly give indications about the future.

Raising this issue with a fellow journalist I got this answer: “stop being a semantic prick! People are not read in mathematics and they know that when we use “exponential” we do it as a synonym for “very quick and fast grow”.

Well, maybe I am a “semantic prick” – aren’t we, lawyers?  – but when hard decisions such as putting the whole Italy in quarantine have to be taken, I would expect the decision-makers to ground their assessment on solid basis rather than on a sloppy use (and understanding?) of data and information.

This is not to say that the decision to quarantine Italy is wrong (I neither have the knowledge nor the competence to judge it.) I only point out that there might not be a cause-effect relationship with a (good) decision and the reasons that backed it.

Virus, Statistics and Videogames

It seems to me that the way the Corona Virus numbers are used in this phase of global hysteria does not help in the understanding of the scenario.

Animations and “infographics” about the spread of contagions, deaths counts or the speed at which the virus propagates are ubiquitous, but the criteria used to produce these materials are hardly known, and sometimes there is a suspicion that some of them lack real basic knowledge of how statistics work.

I prevent an (easy) objection: it is true, I am a jurist and not a statistician, so I am not qualified to speak with scientific competence on the subject.

That is true, and indeed I do not intend to. I only use what I learned in mathematics between high school and university and what I studied in statistics by collaborating on the Italian edition of the classic by Darrell Huff, How to lie with statistics, edited and translated by Giancarlo Livraghi (who, as a great advertising man, knew the subject perfectly) and by Prof. Riccardo Puglisi (who, as an economist, is equally well versed on the subject).

I do not offer “truth”, therefore, but only doubts in search of answers.

Firstly: unifying the various categories of the deceased makes the sample unbalanced and calculating the mortality rate on an undifferentiated population provides an unreliable result. To establish the death rate of the virus, one should at least differentiate who had other pathologies on the consequences of which the virus was superimposed, from those who were sick of something else but did not know it, from those who were in particular conditions that favoured the expansion of the virus (immunodepression from hyperactivity, for example). This article goes in the right direction, even if the methodological problem of how to use statistics remains.

Secondly: it is one thing to analyse a statistically valid sample; it is another to analyse an unbalanced sample. In other words: if I look for the supporters of a football team in the supporters’ curve, I obtain a clearly different result than if I use a sample – depending on the level of the team – built on a city or national basis. Unbalanced champions can also serve, but you need to be clear about the limits of the knowledge they generate.

Thirdly (and consequently): even transforming the absolute values of deaths and infections in various countries into percentages without adopting weights is methodologically wrong. To say – as Il Giornale does – that the mortality rate is 4% out of 3,858 cases induces an incorrect generalisation when comparing the “raw” ratio between the number of cases and deaths.

Moreover, and concluding: as long as there are no numbers large enough to obtain statistical significance, one should be very cautious in spreading them. If 7 out of 10 or 490,000 out of 700,000 people give a particular answer to a questionnaire, in both cases, we can say that 70% of the respondents pronounced in a certain way. But (without prejudice to the need for a statistically valid sample) each case clearly has a different explanatory power. It would be useful to know, for example, whether the numbers used in a study like this are still too low to be statistically valid or not. In the first case, it would be “only” a frozen-frame of an upgoing video; in the second it would provide information on overall value.

Rereading Darrell Huff’s book, therefore, might not be a bad idea.

Social Network To Privatize Geopolitical Strategies

According to Forbes, Facebook and Twitter have closed accounts of people linked to the Chinese government and used as anti-propaganda on demonstrations in Hong Kong. The decision came after unspecified “investigations”, at the end of which the two companies decided – in fact – to intervene directly by walking into in a matter of domestic policy of a sovereign state, setting a dangerous precedent. Continue reading “Social Network To Privatize Geopolitical Strategies”

Weibo vs Leica Camera AG: Social Networks and the loss of control over corporate brands

An advertising video titled “The Hunt” and aimed at promoting the “Leica experience” raised controversy in China because of a frame showing a lens that mirrors the Tank Man picture portraying the activist that in Tien An Men Square blocked a PRC Tank just refusing to give way.

As a result for what has been perceived as an infringement of the chinese social networking platfrom Weibo terms and conditions, the word “Leica” (both in English and Chinese) is banned from the platform.

Furthermore, the partnership between Leica and HwaWei to establish a Chinese presence of the German camera manufacturer seems to having being jeopardized, at least for now. Continue reading “Weibo vs Leica Camera AG: Social Networks and the loss of control over corporate brands”

There ain’t no such thing as a Russiagate

At the time of the events, Linkedin and the general media were flooded with comments on what was only a hypothesis (Russia’s involvement in conditioning the outcome of the American elections), with the plethora of implications on armies of trolls remotely controlled ? to manipulate consciences etc. etc.. It was a fake, but the damage caused by that news is more than real.

I refer, in particular, to the embarrassing institutional declarations on the gravity of a non-existent fact, not at all mitigated by the inevitable “if confirmed, the news would be serious”.

Fortunately, international diplomacy is still sufficiently keen to avoid the consequences of the “social media frenzy” that has also infected the institutions and that pushes its representatives to speak too quickly. Continue reading “There ain’t no such thing as a Russiagate”