tiểu luận kinh tế lượng econometrics report

TABLE OF CONTENTS I ABSTRACT .4 II INTRODUCTION III LITERATURE REVIEW ………………………………………………… IV THEORETICAL BACKGROUND V DESCRIPTIVE STATISTICS OF DATA .8 Research model 1.1 Research model…… 1.2 Meaning of the parameters…… 1.3 Sign expectation of the parameters………………………………………….10 Statistics description 10 2.1 Graph 10 2.2 Summary statistics ………… 11 Correlation matrix 12 VI ECONOMETRICS MODEL 12 Set up a general model………… 12 Interpret the model……………………………… 14 VII ROBUSTNESS CHECK .15 Multicollinearity 15 Normality .16 Heteroscedasticity 18 VIII FINDINGS AND DISCUSSION 20 General summary 20 Findings and discussion .21 IX CONCLUSION 24 X.REFERENCES I – ABSTRACT Object and scale of the study The aim of the model is to study about the demand for Lemongrass-Kumquat tea of FTU students in 09/2019 by analyzing the factors affecting the demand for Lemongrass-Kumquat tea of them From the perspectives as second-year students and the data collected, we hope to find the way to develop the business of Lemongrass-Kumquat tea stalls in the next few months The data of observations was collected from 53 students of FTU about Lemongrass-Kumquat tea – a recent new common favorite kind of drink among students in big cities of Vietnam Anyway, because of the limited time, we only collected 53 observations, which seems to be not enough to guarantee the exactness of the result of our assignment We will be very appreciated if there are any further researches in the future to help our assignment more completed Study method In the assignment, we used both qualitative method and quantitative method to study the influences of factors affecting the demand for Lemongrass-Kumquat tea of FTU students - Qualitative method: through the investigations about factor affecting the demand of buyers and theoretical background to build research model, then design the questionnaire - Quantitative method: study the factors impacting the demand for LemongrassKumquat tea The method is shown through the processing and analyzing the data II – INTRODUCTION In recent decades, Vietnam have spurred rapid economic growth and development, GDP has risen, people's lives have improved both physically and mentally People in the past had thought that living was just to feed and clothe themselves properly Nowadays, there is a significant change, everyone is looking for a higher enjoyment, better lifestyle and new standard of living Entertainment, food and beverage never before become such a huge demand Especially in big city like Hanoi, students with characteristics of large number and great demand, spread across the market segments, has automatically become an important part Foreign Trade University students is not an exception Through the research process, our group realized that: besides other types of entertainment such as sports, arts, etc., going to tea shop after stressful classes is quite a lot of students' choice Lemongrass-Kumquat tea is booming into a trend in a couple of months lately Walking around the university, we can see many pubs selling this drink Indeed, to find a fresh, diverse flavor, easy to drink, easy to find, perhaps in addition to LemongrassKumquat tea, there is no more suitable drink There is an immense number of factors that affect the purchasing power of customer such as The environment protection awareness of buyer, Safety evaluation, Taste evaluation, Budget of living, services, etc Our group wants to find a topic that apply what we have learned and all members are dedicated to being able to successfully complete the assigned tasks, at the same time meet the urgent needs of society, and must also be very close to be able to apply immediately reality That is the reason why our team decided to select the topic " Factors affecting buying power of Lemongrass-Kumquat tea of FTU students" With a sample size that is not too large, easy to implement to achieve the most accurate results, high applicability, practical issues III – LITERATURE REVIEW In recent years, especially in 2019, the trend of young people looking for their favorite drinks has started to become more subtle The favorite drinks of young people often bring many benefits for health, physique and physicality Seeing the increasing demand for the Lemongrass-Kumquat tea among students, we found this issue having many interesting factors to study Since there are few assignments researched about the demand for the Lemongrass- Kumquat tea, especially researching the needs of this drink of Foreign Trade University students Therefore, we studied this topic through the way reading these books, materials related customer psychology We recognized some factors affecting demand, for instance: price, quality, service A decision-making style is defined as a "mental orientation characterizing a consumer's approach to making choices." Sproles and Kendall (1986) developed a consumer style inventory (CSI) consisting of eight factors, such as price-sensitivity, quality-consciousness, brand-consciousness, novelty-seeking, fashion-consciousness and habit Based on these factors, the authors developed a typology of some distinct decision-making styles:  Price-conscious: A consumer who exhibits price-and-value consciousness Price-conscious shoppers carefully shop around seeking lower prices, sales or discounts and are motivated by obtaining the best value for money  Quality conscious/Perfectionist: Quality-consciousness is characterized by a consumer's search for the very best quality in products; quality conscious consumers tend to shop systematically making more comparisons and shopping around to compare quality and value  Brand-conscious: Brand-consciousness is characterized by a tendency to buy expensive, well-known brands or designer labels Those who score high on brand-consciousness tend to believe that the higher prices are an indicator of quality and exhibit a preference for department stores or top-tier retail outlets  Habitual / brand loyal: characterized by a consumer's tendency to follow a routine purchase pattern on each purchase occasion; consumers have favorite brands or stores and have formed habits in choosing, the purchase decision does not involve much evaluation or shopping around However, when we applied these factors into real life, specially the demand of Foreign Trade University students for Lemongrass-Kumquat tea, our research subject is in a narrow range, we have known that these factors such as gender, age (19-20-21-22 years old) and price (10,000VND/ cup) not affect strongly on customer demand After discussing and examining with together, we determined to choose taste, service, enjoyment factors into our research IV – THEORETICAL BACKGROUND Water accounts for 65-70% of body weight, is the environment in the metabolism between inside and outside the cell We can fast for a long time, but we cannot abstain from drinking When losing 20-25% of water in the body, we will feel uncomfortable, born hallucinations, the situation can not last long In addition, when the body is dehydrated, it will lead to the loss of mineral salts and thereby lead to the imbalance of salt in the body So in many cases, people need to add about 1% of table salt to drinking water or mineral water to ensure the body stabilizes the amount of salt in the body And since then to improve and enhance the quality of drinking water, people have added many other ingredients such as sugar, salt, flavor enhancers and preservatives In some cases, people add a small amount of stimulants (caffeine), sedatives, diuretics, health supplements (like in herbal soft drinks), digestive aids, etc These components have changed according to customs and practices of each region and each locality Drinking water has been improved, more and more developed, from which the beverage manufacturing industry was born There may be many ways to classify soft drinks, but generally soft drinks are classified into two categories, alcoholic beverage and the second is non-alcoholic beverage In the group of non-alcoholic beverages, we can mention familiar drinks such as soft drinks (including two types, carbonated and non-carbonated soft drinks, juice, they are almost essential items and cannot be absent in daily life The beverage market in Vietnam is currently developing at an extremely fast pace The number of soft drinks is increasingly diversified, rich with products such as Cocacola, Pepsi, which are produced from domestic as well as abroad Demand for soft drinks is met with better beverage companies and better care But looking at the reality of Vietnam, the beverage industry is extremely diverse and plentiful, such as the Street beverage market It is extremely popular in Vietnam, and extremely convenient for everyone And over time, street refreshments have become familiar with Vietnamese people, especially the young students According to our observations at the street beverage cabaret, students often gather here a lot after school They talk to each other, and enjoy drinks such as “Tra da”, a popular drink However, drinking “Tra da” is forced to sit in one place Therefore, another needs are gradually formed and developed, they want convenient drinks such as street refreshments but can be taken away Therefore, a number of fruit teas such as lemon tea, kumquat tea, peach tea, and especially lemongrass kumquat tea have been added to the student's list of convenient and favorite drinks And especially FTU students have the need to use lemongrass kumquat tea more and more because it not only fits the student's budget but also suits their interests Realizing that this is a good, interesting topic, we have decided to research and explore this topic V – DESCRIPTIVE STATISTICS OF DATA About the research model 1.1 Research model The demand for the Lemongrass-Kumquat tea of FTU student 09/2019 is estimated through the amount of money (million vnd) they spent on LemongrassKumquat tea The demand is influenced by these below factors:  EviProAware: The environment protection awareness of buyer ( The LemongrassKumquat tea is sold by plastic cups, which increases the amount of plastics to environment It causes the environment pollution problem to be more serious ) Code if you are highly aware of it and try protect environment; Code if you are  aware of it but nothing; Code if you are not aware of it SafetyEva: Safety evaluation about Lemongrass-Kumquat tea of buyer Code Very bad; Code Bad; Code Neutral; Code Good; Code Very Good  TasteOfLKT: Taste evaluation about Lemongrass-Kumquat tea of buyer Code Very bad; Code Bad; Code Neutral; Code Good; Code Very Good  BugdetLiving: Budget of living (million vnd)  ServiceEva: Evaluation about service at stall Code Very bad; Code Bad; Code Neutral; Code Good; Code Very Good PRF: AAM = β0 + β1 EviProAware + β2 SafetyEva + β3 TasteOfLKT + β4 BudgetLiving + β5 ServiceEva + ui 1.2 Meaning of the parameters - β0: Intercept - β1: The change in “The average amount of money spent on Lemongrass-Kumquat tea” according to “Environment protection awareness” of buyer - β2: The change in “The average amount of money spent on Lemongrass-Kumquat tea” according to “Safety evaluation about Lemongrass-Kumquat tea” of buyer - β3: The change in “The average amount of money spent on Lemongrass-Kumquat tea” according to “Taste evaluation about Lemongrass-Kumquat tea” of buyer - β4: The change in “The average amount of money spent on Lemongrass-Kumquat tea” according to “Budget of living per month” of buyer - β5: The change in “The average amount of money spent on Lemongrass-Kumquat tea” according to “Evaluation about service at stall” of buyer - ui: error term 1.3 Sign expectation of the parameters (*) AAM = The average amount of money spent on Lemon-Kumquat tea Depending on the theoretical background and our real-life experience, we expect: - The “Evironment protection awareness” should have the positive relationship with “AAM” OR: β1 should be negative (+) - The “Safety evaluation about Lemon-Kumquat tea” should have the positive relationship wih “AAM" OR: β2 should be positive (+) - The “Taste evaluation about Lemongrass-Kumquat tea” should have the positive relationship with “AAM” OR: β3 should be postive (+) - The “Budget of living per month” should have the positive relationship with “AAM” OR: β4 should be positive (+) - The “Service evaluation at stall” should have the positive relationship with “AAM” OR β5 should be positive (+) Statistics description 2.1 Graph Graph 1: Actual plots and fitted line, using observations – 53 2.2 Summary Statistics Table 1: Main summary statistics, using observations – 53 Correlation Matrix Table 2: Correlation coefficients, using observations 1- 53 (*) The model has no autocorrelation VI – ECONOMETRICS MODEL Set up a general model (regression model) We have a research model as below: PRF: AAM = β0 + β1 EviProAware + β2 SafetyEva + β3 TasteOfLKT + β4 BudgetLiving + β5 ServiceEva + ui Our regression model is like below: PRF: AAM = b0 + b1 EviProAware + b2 SafetyEva + b3 TasteOfLKT + b4 BudgetLiving + b5 ServiceEva + ei Using the OLS method, we come up with this table: Table 3: OLS, using observations 1-53 According to the table, we can estimate the coefficients: - b0 = -0.191413 - b1 = 0.0200984 - b2 = 0.0148653 - b3 = 0.0302317 - b4 = 0.0188710 - b5 = 0.0171528 As the result, we can rewrite the sample regression function as: = -0.191413 + 0.0200984 EviProAware + 0.0148653 SafetyEva + 0.0302317.TasteOfLKT + 0.0188710.BudgetLiving + 0.0171528.ServiceEva Interpret the model - Intercept β0 = -0.191413 indicates that when EviProAware, SafetyEva, TasteOfLKT, BudgetLiving, ServiceEva in each state are 0, the average amount of money spent on Lemongrass-Kumquat tea with the lowest value is -0.191413 - β1 = 0.0200984 indicates that when other explanatory variables remain unchanged, if EviProAware raises 1%, the average amount of money spent on Lemongrass-Kumquat tea increases 0.0200984 - β2 = 0.0148653 indicates that when other explanatory variables remain unchanged, if SafetyEva raises 1%, the average amount of money spent on Lemongrass-Kumquat tea increases 0.0148653 - β3 = 0.0302317indicates that when other explanatory variables remain unchanged, if TasteOfLKT raises 1%, the average amount of money spent on Lemongrass-Kumquat tea increases 0.0302317 - β4 = 0.0188710 indicates that when other explanatory variables remain unchanged, if BudgetLiving raises 1%, the average amount of money spent on Lemongrass-Kumquat tea increases 0.0188710 - β5 = 0.0171528 indicates that when other explanatory variables remain unchanged, if ServiceEva raises 1%, the average amount of money spent on Lemongrass-Kumquat tea increases 0.0171528 - R-square = 0.848227 show that: 84.8227% of the variation in the average amount of money spent on Lemongrass-Kumquat tea is explained by variables VII – ROBUSTNESS CHECK Multicollinearity 1.1 General theory In statistics, multicollinearity (also collinearity) is a phenomenon in which one predictor variable in a multiple regression model can be linearly predicted from the others with a substantial degree of accuracy In this situation the coefficient estimates of the multiple regression may change erratically in response to small changes in the model or the data Multicollinearity does not reduce the predictive power or reliability of the model as a whole, at least within the sample data set; it only affects calculations regarding individual predictors That is, a multivariate regression model with collinear predictors can indicate how well the entire bundle of predictors predicts the outcome variable, but it may not give valid results about any individual predictor, or about which predictors are redundant with respect to others 1.2 Check Multicollinearity (*) If model has the statistical significance, it does not have check the multicollinearity But in our case, the model does not have the statistical significance, we will check it through the table below If a VIF > 10, the model has high collinearity and we have to cure it Table 4: Variance Inflation Factors, using observations 1-53 As we can see, VIF of all variables are below 10, even very close to That means the factors are not impacted by correlation with others, so the model is strong! Normality 2.1 General theory In statistics, normality tests are used to determine if a data set is wellmodeled by a normal distribution and to compute how likely it is for a random variable underlying the data set to be normally distributed 2.2 Check Normality (*) As usual, with more tha 30 observations, we can somehow guarantee the normality Anyway, to make sure the model has a normal distribution, we will check through the graph below Hypothesis H0: Normally distributed ( If p-value ≥ 5%, H0 is accepted and our model has a normal distrubution p-value < 5%, H0 is rejected and our model does not have a normal distribution) According to the graph, Chi-square equals to 2.169, and the p-value = 0.3381 > 0.05 At a 5% level of significance, we have enough evidence to accept H 0, or our model has a normal distribution Heteroscedasticity 3.1 General theory The word “heteroscedasticity” comes from the Greek, and quite literally means data with a different (hetero) dispersion (skedasis) In simple terms, heteroscedasticity is any set of data that isn’t homoscedastic More technically, it refers to data with unequal variability (scatter) across a set of second, predictor variables 3.2 Check Heretoscedasticity (*) Cross-section data is more likely to have heretoscedasticity than other types of data Let us check if our model have heretoscedasticity or not through the table formed by White’s test below: Hypothesis H0: var(ui) = ⸹2 H1: var(ui) = ⸹i2 ( If H0 is rejected, the model has herotoscedasticity ) Table 5: White’s test for heteroscedasticity, using observations 1-53 As we can see, the p-value = 0.114877 > 0.05 At a 5% level of significance, we have enough evidence to accept H0, or our model does not have hetetoscedasticity Summary Table about Robustness check Variable EviProAware SafetyEva TasteOfLKT BudgetLiving ServiceEva Constant N R-square Multicollinearity Autocorrelation Normality Heteroscedasticity Chosen model 0.02009884 (3.652) 0.0148653 (2.902) 0.0302317 (3.340) 0.0188710 (4.944) 0.0171528 (2.852) -0.191413 (-6.761) 53 0.848227 VIF of all variables 0.05 At a 5% level of significance , accept H0: model has a normal distrubution No Normality p-value = 0.114877 > 0.05 At a 5% level of significance ,accept H0: var(ui) = ⸹2 No Heteroscedasticity VIII – FINDINGS AND DISCUSSION General summary After these above parts, we did - Pointing out the theoretical background - Building the research model - Estimating the parameters ( with the data from 53 observations ) - Analyzing the result ( Robustness check ) - Coming into the final conclusion of the best model for the topic: AAM = β0 + β1 EviProAware + β2 SafetyEva + β3 TasteOfLKT + β4 BudgetLiving + β5 ServiceEva + ui Findings and discussion The aim of the assignment is to determine and understand the factors affecting the demand for Lemongrass-Kumquat tea of FTU students in 09/2019 According to the research, the demand for Lemongrass-Kumquat tea of FTU students in 09/2019 depends on several factors To determine the impact of those factors, a regression model is built and tested Although the number of observation is not so big, we’re glad: the result after analyzing the data collected from the questionnaire shows the scales measuring the demand are trustworthy and have statistical significance We can tell from the model that there are kinds of factors affecting the demand for Lemongrass-Kumquat tea of FTU: subjective factors (Environment protection awareness, Budget of living per month) and objective factors (Safety, Taste, Service) After discussing about the data collected and the result that we got through the gretl, we did find out some problems Firstly, we want to mention the subjective factors Subjective factors are the factors that the sellers hardly can make any change to In the model, “Environment protection awareness” is positively associated with the demand It means: the higher awareness of environment protection is, the less they buy the tea (Read the research model to understand) The environment is becoming the top of the most concerning problem all over the world The amount of plastics thrown to the nature excessed our expectation As being FTU students – not only good at specialty but also highly aware of social problems, ones who doesn’t aware of this is minority With the view of developing the business in the future, when they highly aware of this environmental problem, the sellers should adapt the situation by changing from plastics cup & straw to environmentally friendly materials The other subjective factor, “Budget of living per month” of the buyers, is also positively associated with the demand It means the higher the budget is, the more they buy the tea Although sellers cannot intervene buyers’ budget of living, at this time, they not need to worry because the majority of FTU students have the high budget of living In other word, they have a financial potential to afford a huge amount of Lemongrass-Kumquat tea if they want Secondly, we want to mention the objective factors Objective factors here are the factors that the sellers can make change to In the model, “Safety evaluation about Lemongrass-Kumquat tea” is positively associated with the demand It means the higher safety of the tea buyers think, the more they buy the tea To make the tea look more clean/safe, we recommend each Lemongrass-Kumquat tea stall should make a good decoration; change the bad-looking or old equipment, tools into new bright ones, use the glove/ often clean the hands In the model, there is another objective factor, “Taste” “Taste evaluation Lemongrass-Kumquat” is positively associated with the demand It means the better taste of Lemongrass-Kumquat tea buyers think, the more they buy the tea We can see from “Summary Statistics”, though the maximum point for taste is 5, no one gave the taste point ( maximum point from buyer is ) Maybe LemongrassKumquat tea just stops at being cool iced drink, something to quench the thirst It haven’t reached the expectation about taste of the buyers So, the sellers should continuously differentiate the taste to find out the recipe of tea that can satisfy the most tough buyers The final objective factor is “Service” Service here includes “attitude to serve the customers” and “the ability to satisfy customers in their expected area” In the model, “Evaluation about service at stall” is positively associated with the demand It means the better service is, the more they buy the tea Up to now, the ability to serve customers in expected time is highly evaluated But the attitude to serve customers is not good enough to fulfill the expectation of customers Being only stalls on the street, the LemongrassKumquat tea stalls not need to have a careful customer care system But at least, try to smile warmly and give them a welcomed words! We believe there are many factors that can affect the demand for LemongrassKumquat tea of FTU students, which we not consider putting into the variables of the model for this demand We will continue to research and set up a more updated and perfect model, which helps the Lemongrass-Kumquat tea business grow better In general, from the result of this assignment, sellers should focus to improve the safety, taste, services and try to adapt to the current awareness of environment protection of FTU students so that the demand for Lemongrass-Kumquat tea will be enhanced IX – CONCLUSION Based on the background of the tested model, we can determine and understand the factors affecting the demand for Lemongrass-Kumquat tea Moreover, we can have the knowledge foundation to give recommendations for the sellers in order to boost the demand for Lemongrass-Kumquat tea among FTU students We hope our model we set up and recommendations from 2nd year students’ perspectives will help the LemongrassKumquat tea business flourish not only in FTU’s area but every places in Hanoi X – REFERENCE Introduction to Econometrics Brief edition - James H Stock, Mark W Watson https://en.wikipedia.org/wiki/Multicollinearity https://en.wikipedia.org/wiki/Consumer_behaviour https://123doc.org/document/5152896-tieu-luan-tinh-hinh-sudung-nuoc-giai-khat-cua-sinh-vien-dai-hoc-ngoai-thuong.htm? fbclid=IwAR15_Jw_Cn2RME0zLmJlzHtc4MiGDfXEAikN5YQe 60vILpCASsUaUCBbCIU http://baolongan.vn/thi-truong-nuoc-giai-khat-duong-pho-khoidong-mua-nang-nong-a35671.html ... Graph 10 2.2 Summary statistics ………… 11 Correlation matrix 12 VI ECONOMETRICS MODEL 12 Set up a general model………… 12 Interpret the model………………………………... 2: Correlation coefficients, using observations 1- 53 (*) The model has no autocorrelation VI – ECONOMETRICS MODEL Set up a general model (regression model) We have a research model as below:... business flourish not only in FTU’s area but every places in Hanoi X – REFERENCE Introduction to Econometrics Brief edition - James H Stock, Mark W Watson https://en.wikipedia.org/wiki/Multicollinearity