tiểu luận kinh tế lượng factors affecting average height of countries in the world

FOREIGN 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 – K57 Major: Japanese International Business Instructor: Assoc Prof Dr Tu Thuy Anh Hanoi, October 2019 TABLE OF CONTENTS I ABSTRACT II INTRODUCTION III LITERATURE REVIEW IV THEORETICAL BACKGROUND Human height 1.1 Human height 1.2 Human height around the world Factors affecting the average height of countries 2.1 Health expenditure 2.2 Air quality index (AQI) V DESCRIPTIVE STATISTICS OF DATA Research model 1.1 Overview of the study 1.2 Sign expectation of the parameters 1.3 Meaning of the parameters Statistics description 10 2.1 Graph 10 2.2 Summary statistics 10 Correlation matrix 11 VI ECONOMETRICS MODEL 11 Regression model (OLS method) 11 Testing an individual regression coefficient (T-test) .12 Testing the overall significance (F-test) 13 VII ROBUSTNESS CHECK 13 Multicollinearity 13 Normality 14 Heteroscedaticity 14 VIII FINDING AND DISCUSSION 15 Finding 15 Discussion 15 IX CONCLUSION 17 REFERENCES 18 APPENDIX 19 I ABSTRACT In the developing lives nowadays, height is a problem of which everyone is concerned Not only directly related with health, it is also a basic requirement of many 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’s final height After that, through various research processes regarding the components that can affect human height in many countries, it came to the final conclusions, showing that nutrition is the major factor which has the most effect on height 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 besides nutrition and genetic which also has the significant effect on the average human height around the world Recent studies showed that the Vietnamese male placed 19 th among the countries which has the lowest average height, which is 164,4cm, Vietnamese female placed 13 th among the countries which has the lowest average height around the world, approximately 153,4cm From here, we want to give out some recommendations for improving the average height for Vietnamese people II 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 by day From there, there is a lot of elements directly and indirectly influencing the average height of the citizens of different countries in the world This studies will focus on analyzing those factors We hope it will contribute for other researchers to keep 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 factors are to the average heights Once the regression equation is estimated, the robustness will be checked, and the significance of individual variables can be determined 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 of people K Silventoinen (Journal of biosocial science, 2003) has conducted a research about determinants of variation in adult body height According to this research, final body height is achieved as the result of a combination of genetic and environmental factors The most important non-genetic factors affecting growth and adult body height are nutrition and diseases Short stature is associated with poorer education and lower social position in adulthood This is mainly due to family background, but other environmental factors in childhood also contribute to this association Body height is a good indicator of childhood living conditions, not only in developing countries but also in modern Western societies Future studies combining different scientific traditions in auxology 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 a research about factors affecting the height of children (from to years old) The study use both quantitative and qualitative methods to build research model and questionnaire, then analyze and process the data (using Eviews) to get the results about the children’s height and factors affecting that height They concluded that there are three main factors: genetic factors, nutrition and sex hormone A student (Nguyen Thi Hoa) from Thang Long University has also conducted a research about factors affecting the body growth of people She has pointed out that there are two main determinants that affect the body growth: genetic factor and nutrition Between the two factors, genetic factors have the strongest effect The methods used to research in this study include theoretical research, questionnaire survey and biological analysis Another similar research on people’s height is “Early life factors are determinants of female height at age 19 years in a population” (The Journal of Nutrition, Volume 136, Issue 2, 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 social background on height of adolescent girls at age 19 in the city of Pelotas, Southern Brazil They pointed out that the significant determinants of height were family income, maternal pregestational weight, maternal height, smoking during pregnancy, birth weight, height gain, and age at menarche The methods used to research in this study include theoretical research, questionnaire survey, mathematical statistics and econometric methods An authors team (P.Grasgruber, M.Sebera, E.Hrazdíra, J.Cacek, T.Kalina) has conducted a research about major correlates of male height The purpose of this study 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 compared with the average consumption of 28 protein sources (FAOSTAT, 1993–2009) and seven socioeconomic indicators (according to the World Bank, the CIA World Factbook and the United Nations) This comparison identified three fundamental types of diets based on rice, wheat and milk, respectively The consumption of rice dominates in tropical Asia, where it is accompanied by very low total protein and energy intake, and one of the shortest stature in the world Another authors team (P.Grasgruber, J.Cacek, T.Kalina, M.Sebera) has also conducted a research “The role of nutrition and genetics as key determinants of the positive height trend” The aim of this study was to identify the most important variables determining current differences in physical stature in Europe and some of its overseas offshoots such as Australia, New Zealand and USA They collected data on the height of young men from 45 countries and compared them with long-term averages of food consumption from the FAOSTAT database, various development indicators compiled by the World Bank and the CIA World Factbook, and frequencies of several genetic markers Their analysis demonstrates that the most important factor explaining current differences in stature among nations of European origin is the level of nutrition, especially the ratio between the intake of high-quality proteins from milk products, pork meat and fish, and low-quality proteins from wheat The six above studies have all indicated noteworthy figures and findings about factors affecting people’s height all around the world However, they all focus on genetics and nutrition, what means there are currently no completed econometric study which mentions the social factors like AQI, health expenditures, Moreover, very few studies have mentioned our country, Vietnam Therefore, we think it is necessary to conduct a research on this topic to help change the mindset of Vietnamese people about height that would lead to the optimization of physical growth in children and maximization of the genetic potential, both at the individual and national level IV THEORETICAL BACKGROUND Human height 1.1 Human height Human height, or another name for it is stature, is the distance from the bottom of the feet to the top of the head of a human body, standing erect It is measured by using a stadiometer, usually in centimeters when using the metric system, or feet and 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 small stature 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 The progression of human height may serve as an indicator for two major welfare factors regarding human, which are nutritional quality and health In places where there is war or poverty, environmental factors like chronic malnutrition may result in delayed growth or marked reductions in adult stature even without the presence of any of these medical conditions The study of height is known as auxologist Growth has long been considered as a measure of the health of individuals, hence part of the reasoning for the use of growth charts For individuals, as indicators of health problems, growth trends are tracked for significant deviations and growth is also monitored for significant deficiency from genetic expectations Genetics is a major factor in determining the height of individuals, though it is far less influential in regard to differences among populations Average height is relevant to the measurement of the health and wellness (standard of living and quality of life) of populations 1.2 Human height around the world When populations share genetic background and environmental factors, average height is frequently characteristic As with any statistical data, the accuracy of such data may be questionable for various reasons: - Some studies may allow subjects to self-report values Generally speaking, selfreported height tends to be taller than its measured height, although the overestimation of height depends on the reporting subject's height, age, gender and region - 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 Factors affecting the average height of countries Regarding this study, the two variables of the model to assess their influence on the average height of countries we decided to use are the parameters of health expenditure and air quality index 2.1 Health expenditure Health spending includes health and health-related expenditures Expenditures are defined on the basis of their primary or predominant purpose which is improving health, regardless of the primary function or activity of the entity providing or paying for the associated health services According to the System of Health Accounts, health care covers all activities with the primary purpose of improving, maintaining and preventing the deterioration of the health status of individuals and mitigating the consequences of ill-health through the application of qualified health knowledge (medical, paramedical and nursing knowledge, including technology, and traditional, complementary and alternative medicine (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 health financing National health accounts trace the financing as it flows from sources which provide the funds to agents who decide on the use of the funds to providers and beneficiaries of health services Data will be obtained through technical contacts in country or maybe from publicly reliable documents and reports in instances where not all countries have or update national health accounts and By using various accounting techniques 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 you information about the level of cleanliness or pollution of the air in the area you are searching and related health problems that may affect you if there is a period of very poor air quality, such as an air pollution episode, AQI focuses on health issues that you 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 - 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 and studies of the health effects of air pollution, so AQI levels for each type of health impact 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 V DESCRIPTIVE STATISTICS OF DATA 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 of countries in the world Data was collected from existing sources about 45 different countries - 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 AQIi ncapitalcity and Health expenditure are considered as independent variables (also binary 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 that air 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 be shorter For that reason, β1 should be negative (-) On the contrary, the expenditure in health has the positive relationship with the average 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 - β1 : the change in average height according to the level of air pollution - β2 : the change in average height according to health and health-related expenditures - ui : error term Statistics description 2.1 Graph Graph 1: Actual plots and fitted line, using observations 2.2 Summary statistics Table 1: Main summary Statistics, using observations 10 Correlation matrix Table 2: Correlation Coefficients, using observations VI ECONOMETRICS MODEL Regression model (OLS method) We have the research model as follow: PRF: Average male height = β0 + β1 AQI incapitalcity + β2 Health expenditure + ui Our regression model: SRF: Average male heıght = b0 + b1 AQI incapitalcity + b2 Health expenditure + ei Using the OLS method, we come up with this table: Table 3: OLS, using observations According to this table, we have estimated the coefficients: - b0 = 174.892 11 - b1 = −0.0268172 - b2 = 0.000823998 As a result, we can rewrite the sample regression function as: Averagemaleheıght = 174.892 + −0.0268172.AQI incapitalcity + 0.000823998.Health expenditure Besides, we have R2 = 0.406031, which means that the independent variables can explain approximately 40,6031% the change of the dependent variable Testing an individual regression coefficient (T-test) - Testing the coefficient β0: Hypothesis H0: β0 = H1:β0≠0 (If β0 = 0, this coefficient has no statistical significance) According to table 3, p-value = 1.36e-060 < 0.05 *Conclusion, with the significance level of α = 5%, we reject hypothesis H0 β0 has statistical significance - Testing the coefficient β1: Hypothesis H0: β1 = H1:β1≠0 (If β1= 0, this coefficient has no statistical significance) According to table 3, p-value = 0.0021 < 0.05 *Conclusion, with the significance level of α = 5%, we reject hypothesis H0 β1 has statistical significance - Testing the coefficient β2: 12 Hypothesis: H0:β2=0 H1:β2≠0 (If β2 = 0, this coefficient has no statistical significance) According to table 3, p-value = 0.0047< 0.05 *Conclusion, with the significance level of α = 5%, we reject hypothesis H0 β2 has statistical significance Testing the overall significance (F-test) Hypothesis H0:β1=β2=0 H1:β1≠β2≠0 According to table 3, p-value (F) = 0.000018 < 0.05 *Conclusion, with the significance level of α = 5%, we reject hypothesis H0 The independent variables can explain approximately 40,6031% the change of the dependent variable VII ROBUSTNESS CHECK Multicollinearity The variance inflation factor (VIF) is the ratio of variance in a model with multiple terms, divided by the variance of a model with one term alone Table 4: Variance Inflation Factors, using observations *Conclusion: because the VIF values of all variables are less than 10, it indicates that the model does not have multicollinearity 13 Normality Hypothesis H0: Normally Distributed H1: Not Normally Distributed (If H0 is rejected, our model is not normally distributed) *Conclusion: We have p-value = 0.7130 > 0.05 With a 5% significance level, the model has a normal distribution Heteroscedaticity In order to know whether our model is hereroscedasticity or not, we use White’s test Hypothesis H0: var (ui) = δ ଶ H1: var (ui) = δi (If is rejected, our model is heteroscedasticity) 14 Table 5: White’s test for heteroscedasticity, using observations *Conclusion: We have p-value = 0.419803 With a 5% significance level, heteroscedasticity is not presented VIII FINDING AND DISCUSSION Finding After going through the parts: - Pointing out the theoretical background - Building up the research model - Evaluating the parameters - Analyzing the result (Robustness check and fix if needed) The best model we recommend is: Averagemaleheight = β0 + β1 AQIincapitalcity + β2 Healthexpenditure + UI Discussion The purpose of studying this model is to detect and understand the factors that affect the average height of countries in the world After conducting the research, we 15 obtained the results that the average height depends on both of two factors In order to confirm the effect of these factors, the regression model was built and tested, based on the theory of the theory The results after analyzing the data collected from the survey show that the scales which measuring the average height of countries are reliable and statistically significant First of all we find that health spending is directly proportional to the average height of the people of the countries Accordingly, the higher the per capita health expenditure, means that people are aware of their own health which includes the height of each individual, leading to the average height of that country will be higher And conversely, if every citizen cannot pay for his or her own medical problems, the average height of that country will be lower than the others In order to improve that, every citizen must be aware of his own health care and financial balance to ensure he can afford to pay for medical problems Beside of each individual's awareness of their own health, expenditure parameters can also be affected by a number of external factors such as the state of the economy of each country or the large disparity in population This requires state intervention through policies to promote economic growth or stabilize the national population On the contrary, air quality index is inversely proportional to the average height of the countries The higher the rate of polluted air, the lower the average height It is common for people to live in a heavily polluted atmosphere with industrial emissions, greenhouse effects or the stench of domestic waste, and people can hardly guarantee health in the best way This is one of the major challenges for developed countries with a large proportion of the economy in the economy, requiring the government to take measures to reduce emissions, handle waste properly, and also raising awareness for people on the issue of protecting the fresh air environment 16 IX CONCLUSION As we have mentioned above, Vietnamese male placed 19 th among the countries which has the shortest average height in the world, while the females placed 13 th from the bottom “This is a sad reality If we not improve the height for the young generations right now, we will not be able to get out of this alarming situation.” PhD, Dr Truong Hong Son said There has been many studies looking into the elements affecting the average height of individuals among countries around the world, in this research, we have given out some influencing factors However, we only point out two factors among many many factors regarding the effects on human height, which is “health expenditures” and “air quality index” Therefore, to optimize the growth in height of people around the world in general, and the Vietnamese people, each person needs to be more aware of the importance of health expenditure and air quality index We believe that they should spend their money more wisely, in order to always have a savings in case of treatment and investment in nutrition matters to improve heights Besides, it’s not hard to recognize that industrialization, pollution in air, children suffering from passive smoking, noise pollution, plague, children easily exposed to dangerous viruses, constantly using high dosage of antibiotics for a long period of time, using medications without the consultants and prescription from doctors can a lot of harm to the physical condition and height of small children Each individual needs to have a good sense in protecting themselves In summary, based on the background of our tested model, we are capable of knowing some factors that influence the average height of people in different countries Though this research has many flaws, we hope everyone will be able to aware that besides the two main factors which is nutrition and genetics, there is still many other elements, including those that were not mentioned in our paper Moreover, we truly hope that Vietnamese people can succeed in improving the average height of the nation’s citizens for both genders, male and female 17 REFERENCES Research: K Silventoinen - Determinants of variation in adult body height - Journal of biosocial science, 2003 Pham Thi Han Chien, Duong Thi Mai Duyen, Nguyen Thanh Hang, Ho Ngoc Thu Factors affecting the height of children (from to years old) - Ho Chi Minh City Foreign Trade University Nguyen Thi Hoa - Factors affecting the body growth of people - Thang Long University Denise, P Gigante, Bernardo, L Horta, Rosângela, C Lima, Fernando, C Barros Cesar and G Victora - Early life factors are determinants of female height at age 19 years in a population - The Journal of Nutrition, Volume 136, Issue 2, February 2006 P.Grasgruber, M.Sebera, E.Hrazdíra, J.Cacek, T.Kalina - Major correlates of male height - Economics & Human Biology, Volume 21, May 2016 P.Grasgruber, J.Cacek, T.Kalina, M.Sebera - The role of nutrition and genetics as key determinants of the positive height trend - Economics & Human Biology, Volume 15, December 2014 Data sources: https://en.wikipedia.org/wiki/List_of_countries_by_total_health_expenditure_per_capi ta https://en.wikipedia.org/wiki/List_of_average_human_height_worldwide https://aqicn.org Websites: https://vi.wikipedia.org/wiki/Phép_kiểm_định_Jarque-Bera https://en.wikipedia.org/wiki/Human_height 18 APPENDIX Data table Country Average male height (cm) Health expenditure per capita (US$) AQI in capital city Australia 177.8 4,934 39 Austria 180 4,536 Bahrain 171 119 152 Bosnia and Herzegovina 183.9 431 61 Brazil 170.7 780 49 Bulgaria 175.2 572 88 Canada 175.1 4,508 63 Chile 169.6 1,102 49 China 167.1 426 142 Colombia 170.6 374 78 Croatia 180.4 852 22 Czech Republic 180.31 1,284 59 Denmark 180.4 5,497 25 Dominican Republic 172.7 20 Egypt 170.3 157 104 Estonia 179.1 1,112 16 Finland 180.7 4,005 17 France 175.6 4,026 28 Germany 178 4,592 23 Greece 178.06 1,505 32 Hungary 177.3 894 23 Iceland 181 4,375 64 India 164.7 63 486 Iran 170.3 366 146 Ireland 179 4,757 29 Israel 177 2,756 55 Japan 170.7 3,733 25 19 Kenya 169.6 70 20 Lithuania 177.2 923 63 Mexico 172 535 68 Netherlands 183.2 4,746 46 New Zealand 177 3,554 55 Nigeria 167.2 97 221 Norway 181.6 7,464 42 Poland 178.7 797 23 Qatar 170.8 203 84 Romania 172 442 46 Saudi Arabia 168.9 1,194 65 Singapore 171 228 21 Spain 173.1 2,354 61 Sweden 181.5 56 15 Thailand 170.3 217 50 Turkey 173.6 455 93 United States 175.7 9,536 19 Vietnam 165.7 117 74 20 ... of countries in the world After conducting the research, we 15 obtained the results that the average height depends on both of two factors In order to confirm the effect of these factors, the. .. average height of countries in the world Data was collected from existing sources about 45 different countries - Research model: The average height of countries is influenced by these following factors: ... uncertain whether this sample accurately represents the entire population Factors affecting the average height of countries Regarding this study, the two variables of the model to assess their influence