Factors affecting the average height of countries .... In this research, we decided to focus our research on the other factors besidesnutrition and genetic which also has the significant
Trang 1FOREIGN TRADE UNIVERSITY
FACULTY OF INTERNATIONAL ECONOMICS
-***** -ECONOMETRICS REPORT Topic: Factors Affecting Average Height
Of Countries In The World
Students: Luyen Quang Hieu – 1815520173
Hoang Lan Huong – 1815520176 Pham Thu Hai – 1815520165
Group: 06
Class: English 7 – K57
Major: Japanese International Business
Instructor: Assoc Prof Dr Tu Thuy Anh
Hanoi, October 2019
Trang 2TABLE OF CONTENTS
I ABSTRACT 2
II INTRODUCTION 3
III LITERATURE REVIEW 3
IV THEORETICAL BACKGROUND 5
1 Human height 5
1.1 Human height 5
1.2 Human height around the world 6
2 Factors affecting the average height of countries 7
2.1 Health expenditure 7
2.2 Air quality index (AQI) 8
V DESCRIPTIVE STATISTICS OF DATA 9
1 Research model 9
1.1 Overview of the study 9
1.2 Sign expectation of the parameters 9
1.3 Meaning of the parameters 9
2 Statistics description 10
2.1 Graph 10
2.2 Summary statistics 10
3 Correlation matrix 11
VI ECONOMETRICS MODEL 11
1 Regression model (OLS method) 11
2 Testing an individual regression coefficient (T-test) 12
3 Testing the overall significance (F-test) 13
VII ROBUSTNESS CHECK 13
1 Multicollinearity 13
2 Normality 14
3 Heteroscedaticity 14
VIII FINDING AND DISCUSSION 15
1 Finding 15
2 Discussion 15
IX CONCLUSION 17
REFERENCES 18
APPENDIX 19
Trang 3I ABSTRACT
In the developing lives nowadays, height is a problem of which everyone isconcerned Not only directly related with health, it is also a basic requirement ofmany jobs and work, moreover, it provides a lot of advantages to our daily lives So,which are the factors that determines the human heights in each individual ?
Scientists said that genetic factors take up to 60 to 80% in affecting each person’sfinal height After that, through various research processes regarding thecomponents that can affect human height in many countries, it came to the finalconclusions, showing that nutrition is the major factor which has the most effect onheight According to many researchers from countries around the world, the growth
in physique and body of young children are directly affected from nutrition condition
in their daily meals A child’s height is only 23% influenced by genetic component( from their grandparents and parent’s gene ), while nutrition contributed up to 32%
In this research, we decided to focus our research on the other factors besidesnutrition and genetic which also has the significant effect on the average humanheight around the world Recent studies showed that the Vietnamese male placed
19th among the countries which has the lowest average height, which is 164,4cm,Vietnamese female placed 13th among the countries which has the lowest averageheight around the world, approximately 153,4cm From here, we want to give outsome recommendations for improving the average height for Vietnamese people
Trang 4II INTRODUCTION
Thanks to the many achievements in technology and scientific technique, the world
we are living in nowadays is continuously thriving in every aspect The living quality
of human keeps on being improved, humans get to live in a better conditions day byday From there, there is a lot of elements directly and indirectly influencing theaverage height of the citizens of different countries in the world This studies willfocus on analyzing those factors We hope it will contribute for other researchers tokeep on looking into this topic in a deeper level and rationally give out improvements
on the average height for each individuals
Using the regression analysis, this study can determine how important the factorsare to the average heights Once the regression equation is estimated, therobustness will be checked, and the significance of individual variables can bedetermined performing a T-test on the coefficient of each independent variable
III LITERATURE REVIEW
There are many studies conducted to research about factors affecting the height ofpeople K Silventoinen (Journal of biosocial science, 2003) has conducted a researchabout determinants of variation in adult body height According to this research, finalbody height is achieved as the result of a combination of genetic and environmentalfactors The most important non-genetic factors affecting growth and adult body heightare nutrition and diseases Short stature is associated with poorer education and lowersocial position in adulthood This is mainly due to family background, but otherenvironmental factors in childhood also contribute to this association Body height is agood indicator of childhood living conditions, not only in developing countries but also inmodern Western societies Future studies combining different scientific traditions inauxology are needed to create a more holistic view of body height
Four students (Pham Thi Han Chien, Duong Thi Mai Duyen, Nguyen Thanh Hang,
Ho Ngoc Thu) from Ho Chi Minh City Foreign Trade University have conducted aresearch about factors affecting the height of children (from 0 to 5 years old) Thestudy use both quantitative and qualitative methods to build research model andquestionnaire, then analyze and process the data (using Eviews) to get the results
Trang 5about the children’s height and factors affecting that height They concluded thatthere are three main factors: genetic factors, nutrition and sex hormone.
A student (Nguyen Thi Hoa) from Thang Long University has also conducted aresearch about factors affecting the body growth of people She has pointed out thatthere are two main determinants that affect the body growth: genetic factor andnutrition Between the two factors, genetic factors have the strongest effect Themethods used to research in this study include theoretical research, questionnairesurvey and biological analysis
Another similar research on people’s height is “Early life factors are determinants offemale height at age 19 years in a population” (The Journal of Nutrition, Volume 136,Issue 2, 1 February 2006) conducted by the authors team: Denise, P Gigante,Bernardo, L Horta, Rosângela, C Lima, Fernando, C Barros Cesar and G Victora.The purpose of this study was to investigate the influence of biological and socialbackground on height of adolescent girls at age 19 in the city of Pelotas, SouthernBrazil They pointed out that the significant determinants of height were familyincome, maternal pregestational weight, maternal height, smoking during pregnancy,birth weight, height gain, and age at menarche The methods used to research in thisstudy include theoretical research, questionnaire survey, mathematical statistics andeconometric methods
An authors team (P.Grasgruber, M.Sebera, E.Hrazdíra, J.Cacek, T.Kalina) hasconducted a research about major correlates of male height The purpose of thisstudy is to explore the main correlates of male height in 105 countries in Europe &overseas, Asia, North Africa and Oceania Actual data on male height are comparedwith the average consumption of 28 protein sources (FAOSTAT, 1993–2009) andseven socioeconomic indicators (according to the World Bank, the CIA WorldFactbook and the United Nations) This comparison identified three fundamentaltypes of diets based on rice, wheat and milk, respectively The consumption of ricedominates in tropical Asia, where it is accompanied by very low total protein andenergy intake, and one of the shortest stature in the world
Another authors team (P.Grasgruber, J.Cacek, T.Kalina, M.Sebera) has alsoconducted a research “The role of nutrition and genetics as key determinants of thepositive height trend” The aim of this study was to identify the most important variables
Trang 6determining current differences in physical stature in Europe and some of itsoverseas offshoots such as Australia, New Zealand and USA They collected data onthe height of young men from 45 countries and compared them with long-termaverages of food consumption from the FAOSTAT database, various developmentindicators compiled by the World Bank and the CIA World Factbook, and frequencies
of several genetic markers Their analysis demonstrates that the most importantfactor explaining current differences in stature among nations of European origin isthe level of nutrition, especially the ratio between the intake of high-quality proteinsfrom milk products, pork meat and fish, and low-quality proteins from wheat
The six above studies have all indicated noteworthy figures and findings about factorsaffecting people’s height all around the world However, they all focus on genetics andnutrition, what means there are currently no completed econometric study whichmentions the social factors like AQI, health expenditures, Moreover, very few studieshave mentioned our country, Vietnam Therefore, we think it is necessary to conduct aresearch on this topic to help change the mindset of Vietnamese people about heightthat would lead to the optimization of physical growth in children and maximization of thegenetic potential, both at the individual and national level
IV THEORETICAL BACKGROUND
1 Human height
1.1 Human height
Human height, or another name for it is stature, is the distance from the bottom ofthe feet to the top of the head of a human body, standing erect It is measured byusing a stadiometer, usually in centimeters when using the metric system, or feetand inches when using the imperial system
Height is important, because it is closely connected with other health components,such as life expectancy Studies show that there is a correlation between smallstature and a longer life expectancy Individuals of small stature are also more likely
to have lower blood pressure and are less likely to acquire cancer
Trang 7The progression of human height may serve as an indicator for two major welfarefactors regarding human, which are nutritional quality and health In places wherethere is war or poverty, environmental factors like chronic malnutrition may result indelayed growth or marked reductions in adult stature even without the presence ofany of these medical conditions.
The study of height is known as auxologist Growth has long been considered as ameasure of the health of individuals, hence part of the reasoning for the use ofgrowth charts For individuals, as indicators of health problems, growth trends aretracked for significant deviations and growth is also monitored for significantdeficiency from genetic expectations Genetics is a major factor in determining theheight of individuals, though it is far less influential in regard to differences amongpopulations Average height is relevant to the measurement of the health andwellness (standard of living and quality of life) of populations
1.2 Human height around the world
When populations share genetic background and environmental factors, averageheight is frequently characteristic As with any statistical data, the accuracy of suchdata may be questionable for various reasons:
- Some studies may allow subjects to report values Generally speaking, reported height tends to be taller than its measured height, although theoverestimation of height depends on the reporting subject's height, age, gender andregion
self There could be sampling bias, because the test subject might not have been
chosen, but invited
- Some countries may have significant height gaps between different regions
- Different social groups can show different mean height
- A relatively small sample of the population may have been measured, which makes
it uncertain whether this sample accurately represents the entire population
Trang 82 Factors affecting the average height of countries
Regarding this study, the two variables of the model to assess their influence onthe average height of countries we decided to use are the parameters of healthexpenditure and air quality index
2.1 Health expenditure
Health spending includes health and health-related expenditures Expenditures aredefined on the basis of their primary or predominant purpose which is improvinghealth, regardless of the primary function or activity of the entity providing or payingfor the associated health services
According to the System of Health Accounts, health care covers all activities withthe primary purpose of improving, maintaining and preventing the deterioration of thehealth status of individuals and mitigating the consequences of ill-health through theapplication of qualified health knowledge (medical, paramedical and nursingknowledge, including technology, and traditional, complementary and alternativemedicine (TCAM))
Expenditure is covered on the basis of three questions:
- Where does the money come from (financing, according to the classification of financing schemes, HF)?
- Where does the money go (providers, according to the classification of health care providers, HP)?
- What kind of services and what types of goods are consumed (functionally defined products, according to the classification of health care functions, HC)?
By collect expenditure information within an internationally recognized framework,national health accounts generated these comprehensive and consistent data on healthfinancing National health accounts trace the financing as it flows from sources whichprovide the funds to agents who decide on the use of the funds to providers andbeneficiaries of health services Data will be obtained through technical contacts incountry or maybe from publicly reliable documents and reports in instances where not allcountries have or update national health accounts and By using various accounting
Trang 9techniques depending on the data available for each country, the missing values will
be approximately estimated
2.2 Air quality index (AQI)
Air quality index is an indicator which measures the quality of air daily It gives youinformation about the level of cleanliness or pollution of the air in the area you aresearching and related health problems that may affect you if there is a period of verypoor air quality, such as an air pollution episode, AQI focuses on health issues thatyou may encounter within hours or days after inhaling contaminated air
US EPA calculates AQI with the following elements: NO2, SO2, O3, CO, PM10,and PM2.5
* AQI calculation methods:
- Use simple formula
+ Advantages: simple calculation formula, just using the National Air Standard can determine the value of AQI
+ Disadvantages: Classifications of AQI values corresponding to different health effects are not appropriate by method 3
- Use complex formulas
+ Advantages: Because the table of the above indicators and the below index used
to calculate AQI is determined based on the National Air Environment Standards andstudies of the health effects of air pollution, so AQI levels for each type of healthimpact are consistent with the most realistic
+ Disadvantages: The calculation formula is quite complicated and the construction
of the above index tables and the index is difficult
- Use comparison table
+ Advantages: Simple, easy to identify
+ Disadvantages: Only class AQI levels can be classified but cannot compare two AQI values in the same class
Trang 10V DESCRIPTIVE STATISTICS OF DATA
1 Research model
1.1 Overview of the study
- Object and Scale of the study:
The aim of this model is to study about the factors that affect average height ofcountries in the world Data was collected from existing sources about 45 differentcountries
- Research model:
The average height of countries is influenced by these following factors:
+ AQI incapitalcity: Air quality index measured in the capital city
+ Health expenditure: Health and health-related expenditures
In our research model, Average male height is the dependent variable while AQIincapitalcity and Health expenditure are considered as independent variables (alsobinary variables) We come up with the research model:
Average male height = β0 + β1 AQI incapitalcity + β2 Health expenditure + ui
1.2 Sign expectation of the parameters
Depending on the theoretical background and real-life experience, we can say thatair quality index in capital city has the negative relationship with the average height,which means that if a country’s air is more polluted, people in there tend to beshorter For that reason, β1 should be negative (-)
On the contrary, the expenditure in health has the positive relationship with theaverage height, which means that if a country’s people spend more money on health,they tend to be higher For that reason, β2 should be positive (+)
1.3 Meaning of the parameters
- β0 : intercept