Econometric analysis: Dynamic models in Panel

 

1. Presentation of study data

As part of this project of memory project, we are particularly interested in economic growth in Africa. Variables dictated by literary and empirical journals will be retrieved from the World Bank database. In this case, GDP per capita, fossil energy consumption, physical capital ... etc. Other unobservable variables will be able to be calculated. In this sense, it is the savings rate, the net capital inflow, the rates of commercial opening. Our values are in current dollars. The study period or the interval by which we analyze the theme is between 1960 and 2016. In truth, more data remains unavailable for the year 2017. We will then solicit methods of clearing and correction of the missing values before to be able to carry out studies whose prospects seem already purified in the general introduction.

1. Analyses des résultats économétriques

Table C3.10 shows the estimates of the Dynamic Economic Growth Convergence Test Model using the Arellano-Bond Differential Generalized Moment Method and the Bond-Blundell System. These estimators are consistent if the instruments used are valid (null hypothesis of the Sargan or Hansen test) and there is no autocorrelation (null hypothesis of the Arellano-Bond test). In this context, we realize that there is no conditional convergence of the Solow model in Africa, because its speed of convergence is not accessible with the estimation of the Arellano-Bond and Blundell-Bond estimators. In part, this is due to the presence of 2nd order autocorrelation.

 

 

The method of generalized moments with Arellano-Bover / Bond-Blundell and system difference does not also illustrate an existence of conditional convergence velocity. These estimators are consistent if the instruments used are valid (null hypothesis of the Sargan or Hansen test) and there is no autocorrelation (null hypothesis of the Arellano-Bond test). In this terms, only the GMM in system is valid.

The Anderson-Hsiao and LSDV estimators also prove the lack of convergence in Africa for the Solow model. We have more to do with several diversified economies and especially still nursery We will estimate this time the model Solow increased human capital, approximate the number of students in primary school and compare the results obtained beforehand.

The table opposite shows the results of dynamic panel models. In the literature, as we have already pointed out, there is a variety of dynamic methods, that is to say which includes the endogenous variable delayed by one or more periods. In this sense, we group together a battery of these estimators, among which by the Within autoregressive method (Within_AR (1)), autoregressive generalized least squares method (GLS_AR (1)), Arellano-Bond generalized moment method (Diff_GMM ), generalized moments method of Blundell-Bond (Sys_GMM / BB), generalized method of moments of Arellano-Bover and Blundell-Bond in system and difference (Sys_GMM / AB / Diff_GMM / AB), method of Anderson-Hsiao (IV_GMM ) less square method by dynamic dummy variable (LSDV), orthogonality method (OPM), among others, it happens that the estimators of the method of maximum likelihood in dynamic panel is very competitive that the methods of the moments, but for the sake of a paid application, we will not be able to present it. Despite the coefficient significance of the endogenous explanatory variable, all models show the absence of conditional convergence in Africa.

 

We remind you that the whole of this document is accessible on the Amazon site:

https://www.amazon.fr/Boutique-Kindle-ABDI-BASID-ADAN/s?ie=UTF8&page=1&rh=n%3A672108031%2Cp_27%3AABDI-BASID%20ADAN

ADAN, A.-B. (2018). Croissance Economique et Développement Durable en Afrique: Analyses Statistiques et Econométriques [Kindle]. Amazon Media EU S.à r.l.

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Econometric analysis: Panel Model

1. Presentation of study data

 

As part of this project of memory project, we are particularly interested in economic growth in Africa. Variables dictated by literary and empirical journals will be retrieved from the World Bank database. In this case, GDP per capita, fossil energy consumption, physical capital ... etc. Other unobservable variables will be able to be calculated. In this sense, it is the savings rate, the net capital inflow, the rates of commercial opening. Our values are in current dollars. The study period or the interval by which we analyze the theme is between 1960 and 2016. In truth, more data remains unavailable for the year 2017. We will then solicit methods of clearing and correction of the missing values before to be able to carry out studies whose prospects seem already purified in the general introduction.

 

1. Analyse des résultats économétriques

(4 Significativité des variables exogènes au seuil conventionnels 1%, 5% et 10% : 0.000 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ )

In the results of Table C3.2, the estimates of the basic Solow model and the increase in human capital are shown. The regressions carried out are valid on the assumption that the countries are at their stationary state. The coefficient of the savings rate is not only positive but also very significant. It is perfectly suited to the expected result. This means that the rise in the savings or investment rate has a positive impact on per capita GDP growth.

 

For comparative purposes, the model estimated by dummy or dummy variable scrutinized by the country variable provides a reality opposite to what was expected on the sign of the coefficients compared to that of ordinary least squares. In both models, only the human capital variable of the augmented Solow model is significant with a positive coefficient. We can note that the country variable that has more than 50 modalities is not a better stratification of the studied sample. For this purpose, what about the year variable? This is what we will try to answer with the following estimate.

The least squares estimate by fictitious variable, here taking into account the years show another reality opposite to that by fictitious variable country (country). Rather, the results presented in Table C3.4 are rather close to the ordinary least squares in terms of the signs of the expected coefficients. Again, it is not surprising to see in this case the significance of the variables, because indeed there is a link between production, physical capital and human capital. The definition of the year variable as a dummy variable to measure the specific effect of our sample gives better results than that of grouping by country.

 

 

The grouped estimation method (Pooled) is the most appropriate when each observation is independent of the other. By reducing the observations by a panel observation through the calculation of the average. We have the same results from the least squares method and the fictitious year estimate. Physical capital (savings rate) puts upward pressure on GDP per capita as opposed to human capital. Apart from the comparisons made between the models, it is all the more interesting to determine which model is the most efficient and well suited to test the prediction of the convergence of the Solow model and the increased Solow model.

 

 

We remind you that the whole of this document is accessible on the Amazon site:

https://www.amazon.fr/Boutique-Kindle-ABDI-BASID-ADAN/s?ie=UTF8&page=1&rh=n%3A672108031%2Cp_27%3AABDI-BASID%20ADAN)

ADAN, A.-B. (2018). Croissance Economique et Développement Durable en Afrique: Analyses Statistiques et Econométriques [Kindle]. Amazon Media EU S.à r.l.

 © 2026 The Abdi-Basid Courses Institute (tABCi). All rights reserved.

 

 

🏛️ tABCi Laboratories :

🧪 Abdi-Basid ADAN LABS  | Focus: Interdisciplinary Sciences & Education.

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 © 2017-2026 The Abdi-Basid Courses Institute (tABCi). All rights reserved.

The Unresolved Mysteries of the Universe

 Man, supposed to be the only one, to possess consciousness in the whole of the universe. Despite this, far from knowing everything, master everything on the surface of the globe. Would it be proper, then, to approach here the unresolved mysteries of the universe? Far from disappointment, because with time and future technologies of future generations, we would know a lot to learn nothing that we already know. Many questions are raised and remain unanswered today. Some persist in the most total blur. In this article, we will explain some of these notions including the existence of extraterrestrials and theories of black hole. 

An extraterrestrial, in the sense of a first definition, is a species that would have appeared outside the planet Earth and which would probably be housed in our universe. But astronauts already lived on Earth, their stay in orbit does not correspond to the first conception of the extraterrestrial concept. This thesis coincides with the idea that it is the existence of a life other than that which is common to us. In fact, it is quite plausible that the immense universe is totally empty and that the Earth is at the center of the universe, the nerve core of the big bang theory. In truth, if the NASA (National Aeronautics and Space Administration) constantly investigates the signals of extraterrestrial intelligences. It should be remembered that the true alien is under our skin in this case the soul. This vital breath intervenes in the period of the pregnancy by miracle without scientific explanation or natural cause. In this sense, the second definition follows from this concept. A living being who knows alive beyond the universe is also alive. It means that angels are also extraterrestrials. They come from another life and not from another planet. From another point of view, the flying saucers have shown that they are deprived of any propellant. We are not, in this case, the only one who could have the ability to conceive or the faculty of thought, there are among us others like the demons to consider in this category. They are skilled enough to build devices of these types. 

An ancient Indian civilization tells us about the existence of flying machines of an advanced and unknown technology called the Vimanas. It may be that they are one of  their implementations. Because some of us are collaborating with them (the demons). In sum, the human being is partly earthy and partly extraterrestrial. Further still, he is more extraterrestrial than earthly. In other words, the universe is the largest garden that is offered to the human species or it can be said that there is no extraterrestrial man in the universe. In another article on the principle of the soul, you can discover more details about the principles of the soul. The other subject more mystical than the first is the black hole (also called black ball). 

It is very conceivable to see a theory predicting many phenomena on the universe: Einstein's general relativity, even if Marcel Grossmann and David Hilbert lent their support in mathematics. Last thing which is even more luminous on the knowledge of black hole is the radiation of Hawking, this supposed escape or vaporization during the engulfing of the matter to its surroundings In my opinion, the universe consists of only two components, including a compensating layer of attraction (space-time) and gravitation itself. Each celestial object, homogeneous or not, deforms space-time according to its mass and is automatically infected with it a force of attraction which spreads on all its circumference. Is gravitation the motor of the expansion of the universe? Is it possible to say that she believes with time in intensity? Does not this leave us thinking about the enlargement of the universe and space-time? This is to clarify in this section, is related to the concept of black hole. Equipped with a uniform opening and engulfing all material as it passes. It is a detachment of space-time just like the hole in ozone due to greenhouse gas emissions. Gravitation easily comes out of this hole; indeed, the notion of space-time is no longer to be considered in the center of the black hole. We need to know something that maybe most people will give up in a short time. 

Time exists only for certain subjects. In this sense, it does not apply to beings that are devoid of the materials we make. This is the soul, the demons, the angels. These creatures, the weather does not concern them. And so, gravitation too. He is far from saying that it is amazing to see a flying saucer moving an extraordinary speed. In other words, space-time is a force opposed to gravitation but with a slightly weak intensity. This imbalance perfectly explains the expansion of the universe over time. 

Time, gravitation, space-time intermingles and are limited only on most subjects. Some we still do not know are far from infected. Was the expansion of the universe partly responsible for the movement of celestial objects, just like the planets and asteroids that revolve around the sun? 

Indeed, the swells at the seaside, they too testify to the mobility of the Earth. The secret of the black hole is certainly that which would reveal with more precision possible the birth of the universe. In this case, what message would she leave us with a supernova? An explosion whose epicenter forms a collapse at one point of the universe. One can hardly give up with this thesis, the idea of big bang. The diameter of the black hole does not increase with time. It is the resistance of space-time. Otherwise, it would be catastrophic for humanity. His birth, on the other hand, is vital. The engulfment of the black hole allows only a new construction of space-time and thus for the universe to expand and to be in continuous movement. 

In this sense, we must make a cycle of recreation of the universe by space-time, black hole and gravitation. The visibly dark hole is very concrete that it is conceived of the complex black matter very generative of gravitational force just like the energy stored in the uranium 235. In this condition, the materials which admitted the universe to be formed and those that form by the stars are totally different. In other words, black matter is also the source of other materials that interact with gravitation.

Abdi-Basid ADAN, 2018.

https://www.researchgate.net/publication/326560946_The_Unresolved_Mysteries_of_the_Universe

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The precepts of statistics

 Introduction 

The  concept  of  Statistics,  nowadays,  remains  a  long  time  ago.  It  represents  a discipline  (science)  just  like  any  other,  but  unlike  for  some,  it  is  a  branch  of mathematics for others a field in its own right. This famous expression, however, was born in the 16th century (1771 in French, 1798 statistics in English). Etymologically, it derives  from  the  expression  in  Latin  called  "status"  (state).  Notwithstanding,  its implementation  starts  from  3000  BC  by the  collection  of observations  (census)  on people  or  materials  in  order  to  allow  the  public  decision-maker  to  be  able to  know more their power or their evolution in a specific field (example : Mesopotamia). In addition, Wilcox (1935) identified more than a hundred definitions of the notion of Statistics.  It  is  clear  how  much  this  concept  divides  the  opinions  of  the  scientific community, which remains as puzzling as  we imagine. In this circumstance, Kendall pointed out that this was one of the  things  that  statisticians seem more than ever to oppose about the conception of statistics. In  addition,  the  most  accepted  definition  appeared  in  1982,  announcing  that Statistics  is  a  set  of  methods  whose  purpose  is  to  collect,  process,  interpret  and disseminate statistical data. In general, it is a science that is simply dedicated to data otherwise-says a data science (data science in English).  The statistics (in particular a statistic)  represent  the  processes  by  which  we study  a  set  of  observations  (people, materials, natural  phenomenon,  human  behavior,  chemical species,  plants,  animals ...  etc.  These  are  methodical  approaches  or  Mathematical  magnitudes  (statistical tools)  All  the  more  so,  John  Tukey  considers  the  ramification  of  statistics  in  two approaches that intertwine: exploratory statistics and confirmatory statistics From  a general point of view, Statistics is subdivided into two sections namely the  Descriptive and inferential statistics: The first one  allows  the data to be put in place (census  or  sampling)  then the  one-dimensional and  multidimensional study  of  the studied  and  collected  characters  on  the  observations  (forecast,  Data  Manning, regression,  correlation  ...).  The second  is  more  concerned  with  generalizing with  a margin  of  error  (extrapolation)  the  information  deduced  from  a  representative sample  on  the  entire  population.  To  find  this  information  in  a  very  complex environment,  both  mathematical  and  computer  approaches  are  sought.  Often, various trends in the field of Statistics are suggested. In my opinion, it is primarily at the  service  of  public  decision-makers,  research  and  teaching.I.  Descriptive  or exploratory statistics  

One of  the essential roles  of  statistics  is  the ability  to  extract  vital  information  in  a complex and  structured database, which is not easy with a simple reading. The tools by  which  one  manages  to  do  it  are  various,  some  are  called  parametric  and others non-parametric.  It  is  essential  to  distinguish  between  two  methods  of  descriptive statistics which consist of facilitating information on a set of observations. They may be  synthetic  quantities  or  summary figures  on  the  characters  studied.  Let's  take  a one-dimensional  approach  to  variables.  I  define  it  as  the  speculation  in  a  two-dimensional space  of the  position of  each  observation  with  respect to  a super-point (center of gravity) and on the other hand a grouping according to a specific criterion. Nevertheless,  the  link between  two  variables  is even  more  important because  of its consideration  beyond  the  limited  scope  of  the  first  analysis.  The  dependence,  the strong  connection  or  the  causality  between  two  variables  makes  a  judgment  on  the link  between  two  different  characters  observed  or  not  on  the  same  population. Moreover,  this  introspection  can  be  transferred  to  quite  complex  dimensions  far exceeding  the  perceived  visibility  of  the  eye.  This  is  made  possible  by  the  linear optimization  technique  to  grant  a  feat  that  requires  enough  reduction  without distortion  of  reality.  Descriptive  statistics  are  generally  based  on  three  main approaches: approach  to  a super-point,  clustering approach  according to  a  criterion and  finally  that  which  consists  of  explaining  the  connection  between  two  or  more given phenomena. I II. Mathematical or inferential statistics Statistical  inference  is  initially  non-descriptive  but  rather  inductive.  Because  it consents to estimate an unknown character of a set of observations from a sampling of a sample with well-defined properties. This definition is a means of circumventing the difficulty of accessing very expensive information by an estimate (inference) with the inclusion of a margin of error. The goal is to be able to conclude on the whole with estimators in a judicious and effective way. However, the story of inference begins at the end  of the  nineteenth  century  with  the work  of eminent  mathematicians on  the likelihood, the  test,  the intervals  of  trust,  the quality of  the estimators.  These  works are  experiencing  a  breathtaking  rise  with  the  arrival  of  more  powerful  calculating machines.  In  general,  statistical  inference  techniques  can  be  grouped  according  to two  approaches:  one  based  on  the  estimation  of  the  parameters  of  a  statistical population  and  the  other  on  the  assertion  of  a  hypothesis.  That  is why  it  is,  in  my opinion,  the  only  discipline  capable  of  studying  both  reality  and  unreality  on  the principles of scientificity. As a result, it is competitive  with  other disciplines without distinctions including statistics  and physics have  allowed the major  discovery of the Higgs boson;  statistics  and  mathematics: Shannon's  entropy;  statistics  and  biology: ascending hierarchical classification ... etc.     

In general terms, Statistics is the science that studies data, resurfaces key information in a set of data (just like a treasure in a vault) and makes it possible to better explain all  facts  or  absurd  phenomena.  On  the  other  hand,  it  is  an  instrument  that  goes beyond  the  limit  of  other  sciences  (the  power  of  statistics  or  super  science)  with random estimation techniques.

Abdi-Basid ADAN, 2018.

https://www.researchgate.net/publication/324978899_The_precepts_of_statistics

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Contact : Abdi-Basid ADAN [abdi-basid@outlook.com]

 © 2017-2026 The Abdi-Basid Courses Institute (tABCi). All rights reserved.