tiểu luận kinh tế lượng factors affecting to average spending on cosmetics per month in 2019 of k57 FTU students

FOREIGN TRADE UNIVERSITY FACULTY OF INTERNATIONAL ECONOMICS -*** ECONOMETRICS REPORT Subject: Factors affecting to average spending on cosmetics per month in 2019 of K57 FTU students Lecturer : Dr Tu Thuy Anh Group members : Trần Hồng Hải - 1815520166 Nguyễn Bảo Phúc - 1810520214 Phan Thị Phương Thảo - 1815520222 Hanoi, October 17th 2019 TABLE OF CONTENT I, Abstract II, Introduction III, Literature Review IV, Theoretical Background 1, Income 2, Cost of living 3, Sale off or Discount on cosmetics 4, Concern to cosmetics V, Descriptive Statistics VI, The econometric model VII, Robustness Check 1, Collinearity 2, Normality Test 3, Heteroskedasticity VIII, Findings and discussion 1, Findings 2, Recommendations IX, Conclusion X, References Appendix I, Abstract Cosmetic products are probably the very fundamental objects that every women must have This is a way that helps women feel confident and relax, which is similar FTU girl students However, what are direct factors affecting to average spending on cosmetics per month of FTU girl students? To answer this question, we have researched subject: “Factors affecting to average spending on cosmetics per month of FTU girl students in 2019” And we have found out that financial support from family, extra earning and cost of living affect directly to spend on cosmetics per month Financial support from family and extra earning affect positively and cost of living affect negatively to spend on cosmetics From this result, we have suggested some recommendations for reasonable spending II, Introduction 1, Reasons choosing subject The beauty industry is growing faster than ever before Today it's valued at an estimated $532 billion and counting The rise of beauty vloggers sharing YouTube tutorials and posting about their favorite lipstick on Instagram continues to change the way consumers discover new products and engage with brands In recent years, many cosmetic companies and direct-to-consumer beauty brands have started eschewing traditional advertising altogether, in favor of tapping into the power of influencer marketing and brand ambassadors, not to mention, there is a considerable rise in disposable incomes over the past decade The growth in global economies, changing lifestyles, rising demands of skin and sun care products due to varying climatic conditions encourages the growth of the market for cosmetics The job market for cosmetologists is expected to grow by 16 percent from 2010 to 2020, as fast-cosmetics evolved and the luxury sector ascended It is something that extends to all areas of your life since your appearance affect a large part of who you are as a person It not only makes you feel good but can also largely influence your interaction and equation with people And to girls in their twenties, it is of no exception as this stage of life is considered to be such a cosmetics-sensitive stage, when they are excessively concerned about their appearance Consequently, there is a remarkable need among university student girls to go shopping for cosmetics, and beauty expenditure starts to present a regular part in their monthly spending In order to have a more insightful understanding of university girl students’ cosmetics purchase patterns, we conduct this research under the scope of FTU girl students The title of our econometrics research is: “Factors affecting FTU girl students' average spending on cosmetics per month in 2019” To figure out the relationship between girl’s financial status and their spending on cosmetics, first it is necessary to take a general approach through specifying some of the main factors that would have an effect on students’ decision making when it comes to cosmetics shopping So the purpose of the following literature review will be to address previous related research work on factors affecting customer shopping behaviors for makeup, as well as factors relating to income and expenditure Consequently, several subsidiary problems must first be answered before the problem of evaluating the relationship between spending volume on beauty products and girl financial status can be approached The first issue to be brought up here is about the impact of financial status on customer buying decision The issue would be following presented through smaller questions: What are the main shopping motivations for beauty products? Has financial status been proved a domain factor in manipulating buying decision and whether there is a difference between the behavior of our targeted audience? The issue also raises the question of saving and spending pattern of behaviors among girls and buying behaviors during sales period The second issue goes to the effect of concern about one’s appearance on their spending on makeup Answering these prior questions is essential before inquiring how the relationship between girls’ financial status and their spending on makeup works This line of inquiry supplies the structure for the following review of the relevant literature 2, Purpose of subject - To identify the relationship between the monthly financial status and the monthly spending on cosmetics of FTU girl students 2019 - To suggest some recommendations for reasonable spending 3, Research Methodology - General methodology: Looking for documents, Comparison… - Specific methodology: Survey, Questionnaire, Interview… 4, Structure Apart from table of content, appendix, our research includes: I, ABSTRACT II, INTRODUCTION III, LITERATURE REVIEW IV, THEORETICAL BACKGROUND V, DESCRIPTIVE STATISTICS VI, ECONOMETRICS MODEL VII, ROBUSTNESS CHECK analyzing, VIII, FINDINGS AND DISCUSSION IX, CONCLUSION X, REFERENCE III, Literature Review To figure out the relationship between girl’s financial factors and their spending on cosmetics, first it is necessary to take a general approach through specifying some of the main factors that would affect student monthly income and expenditure and factors and how they verify between male and female Also, it is necessary to look into the factors that would have an impact on shopping pattern, especially cosmetics shopping pattern, among students The primary purpose of this review is to address previous related research work on the above issues About makeup buying behavior, in 2012, W&S Viet Nam as an online market research company had conducted a survey and reported on the Vietnamese shopping habit for cosmetics products Through 396 answers from males and females above 19 years old all over the country, W&S have found out some major information as following: The budget spared for buying makeup is the 3rd biggest in all spending activities, with a percentage of 13.9% of the total personal spending activities When compared between male and females, they also stated that female has a tendency to decide and buy makeup for themselves more than males The subjective of the survey had showed a fairly high frequency of shopping for cosmetics products since 29.8% of them go shopping for cosmetics from to times per week Another point related to the differences in cosmetics purchasing pattern between genders and ages is that: the older they get, the less frequently they go shopping for makeup Besides, price was found to be one of the most important factors in purchasing decisions of consumers When there is sale or discount programs, consumers are motivated to buy more And more recently, many authors has pointed out another factor affecting buying behavior of cosmetics which is culture, with the level of influence moderated by gender And additionally, cosmetics purchase patterns are strong predicted by seasons and special occasions Referring specifically to student’s cosmetics buying behavior, J., O A., & Higby, M A (1993) has suggested in their study that the type as well as level of cosmetics shopping influences are significantly affected by teen age, gender, family size, and gifted money to teens Isabel J Grant and Graeme R Stephen, (2005) has added on this matter by concluding that parental together with peer group plays a key role when it comes to decision-making of “teenage” girls in buying beauty products, and also significant factors affecting their purchasing of cosmetics items are brand name and its associations To look more broadly at how student income and expenditure interacts would also be useful for clarifying more effectively the relationship between university students’ financial status and their spending on cosmetics items In consideration of student income and expenditure, several studies have been conducted to figure out the main sources of money, the categories of spending and the group of attributes of students who would have certain different levels of financial health Firstly, that income does have remarkable impact on student monthly expenditure is the conclusion from the group of author Nguyen Ngoc Hoang Uyen, Tran Thi Hong Nhung, Nguyen Thi Huong Lai, Nguyen Thi My Trang, Nguyen Thi Duc Phuong, Pham Xuan Phuong, Ho Quoc Thanh from the University of Economics Ho Chi Minh City through their research on student’s monthly income and expenditure in Ho Chi Minh city Another research work conducted in the Foreign Trade University in Ho Chi Minh city has gone further the matter of how income and expenditure relates to each other since the authors has found out some of the determiners of and their impact on student monthly spending According to this study, they categorize factors into main factors, which are: the financial support from family, extra income from part-time job, location, gender, characteristic (generous or provident), relationship status (in a relationship or not) Then whether there is a difference between male and female students in income and expenditure, in spending and saving behavior? And how it operates specifically in cosmetics purchase patterns? Chen‐Yu, J H and Seock, Y (2002) has come up with the finding that female participants shopped significantly more often than males and had higher recreation beauty products purchase motivation Then the study of Yoo‐Kyoung Seock, Nicki Sauls, (2008) also revealed some other interesting information: males and females have different shopping orientations and makeup retail store evaluation criteria Also, shopping orientation and cosmetics retail store evaluation criteria also varied across the age groups The above studies and research works have contributed significantly to the understanding of cosmetics purchase behavior and provide useful information on university student financial situation However, no single research has focused on the effect of student financial status on their spending on beauty products, especially within the scope of girl students Therefore, this research should be conducted on the topic to offer more detailed findings about the relationship between girl students’ financial status and their spending on cosmetics to suggest some solutions for more effective financial resources allocation and management Our research below would selectively utilize the information from prior work IV, Theoretical Background For girls students in the generation which concerned a lot about appearance, cosmetíc is one of the most consumed spending Depend on the time, the areas, there are many factors affected girl students’ s spending To see it clearly, we will explain some factors we have chosen 1, Income When mentioning to income of students, we often think the amount of money supported from parents But for many students in university, income also comes from their salaries at part-time jobs They part time jobs to get more experiences and also to earn more money for other spending Theoretically, there are two kinds of income: personal income (PI) and disposable income (DI) Personal income (PI) - Personal income is the sum of all the wages, salaries, profits, interest payments, rents, and other forms of earnings received in a given period of time For students, Personal income is mainly money supported from parents, Parttime jobs, scholarships, their own business… Disposable income (DI) - Disposable income is total personal income minus personal current taxes DI= PI -Taxes However, students don’t have to pay taxes So, their disposable income is personal income They have fully rights to use that money We will consider two main sources of income of students: · Money supported from parents That is amount of money supported monthly by parents to students to help them pay for expense such as shelter, foods… · Money from part-time jobs They want to get more money so that they can spend on something they like or compensate for case they use all money supported from parents So, we can see that income has direct relationship on spending of students If income is higher, consumption will increase If income is lower, consumption will decrease Income = Consumption + Saving According to Macroeconomics, people just save money when the interest rate increases However, for students their income is not too high, so they don’t have much money to save, so the interest rate doesn’t affect to save money in this case Therefore, Income influences most to consumption 2, Cost of living Because many students have to live away from the family to study at university, they have to pay for cost of living Cost of living is often shelter, foods, water, electricity, clothes Average money for cosmetics = Income - Cost of living - others Therefore, Cost of living also affects a lot to average spending on cosmetics monthly of girl students Student’s university life is very expensive, so cost of living is often high Besides some factors we have chosen, there are still other factors but we haven’t yet showed in model However, we still explain to help you see more clearly 3, Sale off or Discount on Cosmetics Cosmetics shops often sale off or discount at some special events such as Christmas, New Year, Black Friday to increase sale volume In this case, students have tendency to buy more because the price is cheaper The income is not too high and the cost of living is very expensive, so at sale, people often buy to save their money An the fact that, the cosmetics goods is high-priced, especially the high-end segments, the goods are tremendously costly So, for the ones who make a litt le money as students, sale off is very attractive and the priority for them to buy 4, Concern to Cosmetics University girl students are in group young people and women cosmetics They have tendency to follow the trendiest beauty products which has huge statistical tests of significance that assume that the modeling errors are uncorrelated and uniform—hence that their variances not vary with the effects being modeled For instance, while the ordinary least squares estimator is still unbiased in the presence of heteroskedasticity, it is inefficient because the true variance and covariance are underestimated And we use White’s test in Gretl to check After running, you will see a pvalue If p- value > 0.05, it not reject Hypothesis that is our model have homoscedasticity This is our result: p-value = 0.142 > 0.05 (You can see more detail at table in Appendix) This result means that our model don’t have heteroskedasticity problem After doing all Robustness check, this is our final model: Y = 0.02 + 0.19X2 + 0.187X3 – 0.115X4 *Note: Unit- Hundred thousand VND + Y: Average money spending on cosmetics per month in 2019 + X2: Average financial support from family per month in 2019 + X3: Average extra earnings per month in 2019 + X4: Average cost of living per month (Food, shelter, water, electric, clothes…) in 2019 VIII, Findings and discussion After having the complete model, now we start to show you some findings and discussion through our model about how factors affect to average spending on cosmetics per month of girl students and what they should to balance the spending 1, Findings a, T-test We look at ts and p-value to see that β is significant or not If ts > tc, or pvalue < α (p-value has stars), it means that β is significant This is our result: + t-ratio of X2 = 3.047 and p-value = 0.0041 has stars β2 is significant + t-ratio of X3 = 3.257 and p-value = 0.0023 has stars β3 is significant + t-ratio of X4 = - 1.696 and p-value = 0.097 has stars β4 is significant (You can see more detail at table2 in Appendix) b, F-test We look at value of F and p-value If Fs > Fc or p-value < α, our model is joint significance This is our result: + F (3, 40) = 5.306 > Fc = 2.92 and p-value (F) = 0.0035 < 0.05 our model is joint significance (You can see more detail at table in Appendix) c, Findings - Var and standard deviation + Var of Y = 16.54, σ = 4.067 It means that observations about average spending on cosmetics per month in 2019 can deviate from Mean about +/- 406,700 VND + Var of X2 = 110.019, σ = 10.489 It means that observations about average financial support from family per month in 2019 can deviate from Mean about +/- 1,048,000 VND + Var of X3 = 95.295, σ = 9.762 It means that observations about average extra earnings per month in 2019 can deviate from Mean about +/- 976,200 VND + Var of X4 = 88.28, σ = 9.395 It means that observations about average cost of living per month in 2019 can deviate from Mean about +/939,500 VND (You can see more detail at table in Appendix) - Square R = 0.285 It means that regressors just explain 28.5% about Y (Average Spending on cosmetics per month in 2019) Therefore, there are other factors affecting to spend on cosmetics per month However, because of time and ability, we just point out three factors They are financial support from family, extra earnings, cost of living - Explanation about model: Y = 0.02 + 0.19X2 + 0.187X3 – 0.115X4 + β1 = 0.02 It means that besides three factors we have shown, other factors affect to average spending on cosmetics per month They increase average spending on cosmetics per month about 2000 VND + β2 = 0.19 It means that when average financial support from family per month increases 100,000 VND, average spending on cosmetics per month will increase 19,000 VND This is similar to our expected direction for X2 It has positively effect on Y + β3 = 0.187 It means that when average extra earning per month increases 100,000 VND, average spending o cosmetics per month will increase 18,700 VND This is similar to our expected direction for X3 It has positively effect on Y + β4 = -0.115 It means that when average cost of living per month increases 100,000 VND, average spending on cosmetics per month will decrease 11,500 VND This is similar to our expected direction for X4 It has negatively effect on Y Through these analysis, we have shown you how financial support from family spending on cosmetics per month of girl students Now, we suggest some recommendations for balancing between income and spending, or some tips for reasonable spending on cosmetics per month of girl students 2, Recommendations a, How to spend money wisely Create a budget Track your spending and income Save receipts or write down your purchases in a notebook Review your bills each month and add those expenses to your budget · Once you've tracked your purchases for a while, create a monthly (or weekly) limit for each category Make sure the total budget is smaller than your income for that period, with enough left-over for savings if possible · Organize your purchases by category (food, clothing, entertainment, etc.) Categories with the highest monthly amounts (or monthly amounts you consider surprisingly high) may be good targets for saving money Plan your purchases in advance so that you can get a view of how much you are going to spend in the future · Make a preliminary trip before you go on your real shopping trip Note the prices of several alternatives at one or more stores Return home without buying anything and decide which products to buy on your second, "real" expedition The more focused you are and the less time you spend in the store, the less you'll spend · If you are motivated to treat each purchase as an important decision, you will make better decisions Avoid impulse purchases - Planning your purchases in advance is a good idea, but there is always a chance that you will break it Follow these tips to avoid making unplanned shopping decisions - Don't browse store windows or shop for fun If you're only buying something because you find the act of shopping fun, you'll likely end up spending too much on stuff you don't need Shop alone - Children, friends who love shopping, or even just a friend can influence you to spend extra money - Do not take advice from store employees If you need a question answered, politely listen to their response but ignore any advice on purchasing decisions If they won't leave you alone, leave the store and return later to make your decision Pay in cash Credit and debit cards increase spending for two reasons: you have much more money available to spend than you normally would, and because there is no visible money, it doesn't appear as a "real" purchase · Don't bring more cash with you than you need If you don't have the extra money, you can't spend it Similarly, withdraw your weekly budget from an ATM once a week rather than filling up your wallet whenever you run out of money Don't be tricked by marketing Marketing influences are a huge factor affecting what we spend our money on Be vigilant and try to be aware of all the reasons you're drawn to a product · Don't purchase something just because it's reduced price Coupons and sales are great for products you were already planning to buy; purchasing something you don't need just because it's 50% off does not save any money at all · Be aware of pricing tricks Notice that "$1.99" almost nothing different from "$2" Judge the price of an item on its own merits, not because it's a "better deal" than another option by the same company · Don't automatically buy the mid-priced product within a category Marketers know that if they want you to buy a high-priced product instead of a low-priced product, they can influence your decision by adding an outrageously expensive product to make the high-priced product intermediate in price and look reasonable in comparison Wait for sales and discounts If you know you'll need to buy an item but don't need it right now, wait until there is a discount or try to find a coupon for it Do your research before making expensive purchases Read consumer reports on the Internet to discover how to get the most bangs for the least buck Find the product within your budget that will last longest and meet your needs best Take all the costs into account You'll end up paying a lot more than the sticker price for many big-ticket items Read all the fine print and add up the total amount before making your decision · Don't be fooled by lower monthly payments Calculate the total amount you'll spend (monthly payments x number of months until fully paid) to find out what the cheapest option is · If you're taking out a loan, calculate how much total interest you'll have to pay b ,Tips for girl students to be pretty with small amount of money Consider carefully before you buy Many students buy redundant products, things they don’t need That’s a waste of money And especially for the cosmetic products, girl must choose carefully because it has a lot of skin types If it cannot be checked carefully, the products would make your skin hurt So you need to consider carefully whether you need this product or not before buying it Would you buy this if there wasn’t any discounts? Even something cheap is a waste of money if you're not going to wear it more than once Still unsure? Sleep on it Nothing haunts us like the things we didn't buy, so if you really want that lipsticks, you'll still be thinking about it tomorrow If you're worried about someone else buying it in the meantime, put it on hold while you decide if you truly have to have it Start shopping early for the things you really need Start shopping from the early month, or even earlier to give yourself the most time to find something you love at the best possible price IX, Conclusion Nowadays, girls tend to care more about the way they look, especially when they are more mature and recognize how important their appearance can affect the impression of other people about them So there is an inclination for girls when they enter university to invest in cosmetics products and to polish the way they look Therefore, we should determine how financial factors affect their spending on cosmetics so that girls can control their expenditure and have an important insight into how they self-manage their finance problems throughout their university years In addition, we can introduce some suggestions for more effective financial management After implementing our research, it has been found that girl students’ average monthly spending on cosmetics is dramatically affected by financial factors: Average financial support from family per month, average extra earnings per month and average cost of living per month as presented above The scope of this research work is limited Although the research addresses the works of most significant researches in the field, constraints and limited access to information means that some major figures have not been included Furthermore, other researches have been concentrating on the factors affecting impulsive customer behavior, decision making, shopping motivators, shopping orientation, buying intention to find out whether they would buy a specific product or not, based on the characteristics of its brand, shopping experience, etc or on the relationship between lifestyle and cosmetics selection criteria for example, or some researches focus on buying behavior of a specific segment of the cosmetics industry according to age while our research focus on the factors that affect how much girl students would generally spend on cosmetics based on their financial status Therefore, despite the relevant examples of these studies, it can be said that this study needs to be redressed by the research community X, References For literature review: ● UKessay, (2016), “Buying Behavior Of Youth Towards Cosmetic Products Marketing Essay”, https://www.ukessays.com/essays/marketing/buying-behavior-of-youthtowards-cosmetic-products-marketing-essay.php ● A,H.Hemanth Kumar, S.Franklin John, S.Senith, (2014), International Journal of Scientific and Research Publications, Volume 4, Issue 9, “A Study on factors influencing consumer buying behavior in cosmetic Products”, https://www.academia.edu/24745631/A_Study_on_factors_influencing_c onsumer_buying_behavior_in_cosmetic_Products Essay Company, (2018) “Teenage Purchasing Decisions for Cosmetics”, ● https://www.essaycompany.com/dissertations/management/consumerbuying-behaviour Lou Hirsh, “Consumer Buying Behavior of Teenagers & How to Market ● to Them” , https://smallbusiness.chron.com/consumer-buying-behaviorteenagers-market-61529.html https://pdfs.semanticscholar.org/d12a/09ec35fc9be74ca13f35fe46558f8ed ● 12bf5.pdf The Beauty Industry's Influence on Women in Society - Ann Marie ● Britton: https://scholars.unh.edu/cgi/viewcontent.cgi? article=1085&context=honors - For theoretical background: + Book: Principles of macroeconomics- N Gregory Mankiw The Psychological Science of Money- Travis J Carter - For robustness check: Link: https://en.wikipedia.org/wiki/Multicollinearity https://en.wikipedia.org/wiki/Heteroscedasticity https://en.wikipedia.org/wiki/Normal_distribution Table Number Y (100,000 VND) 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 1.5 10 2 2 1 5 10 2 10 15 3 11 X2 X3 X4 (100,000 VND) (100,000 VND) (100,000 VND) 35 30 30 20 20 20 15 20 15 20 15 20 10 20 32 25 30 25 40 30 10 25 30 25 30 45 20 20 20 10 20 10 0 35 24 10 10 10 10 20 20 0 12 4 20 10 30 10 13 13 30 16 12 25 0 36 20 15 10 30 12 20 20 30 10 8.85 12 10 20 24 20 25 10 15 10 17 15 30 30 30 22 20 15 7.5 36 37 38 39 40 41 42 43 44 10 15 3 2.5 10 15 30 45 20 27 35 28 40 20 30 10 10 12 10 20 13 15 8.5 10 20 15 28 35 4.5 20 Table Model 1: OLS, using observations 1-44 Dependent variable: Y Coefficient Std Error t-ratio p-value Const 0.0165225 1.63391 0.01011 0.9920 X2 0.190089 0.0623913 3.047 0.0041 *** X3 0.187987 0.0577145 3.257 0.0023 *** X4 −0.11466 0.0675979 −1.696 0.0976 * Mean dependent var 4.727273 S.D dependent var 4.066961 Sum squared resid 508.7627 S.E of regression 3.566380 R-squared 0.284669 Adjusted R-squared 0.231019 F(3, 40) 5.306064 P-value(F) 0.003567 Akaike criterion 240.5694 Hannan-Quinn 243.2161 Log-likelihood Schwarz criterion −116.28 47 247.7062 Table Mean Median Minimum Maximum Y 4.7273 3.0000 0.0000 15.000 X2 23.114 20.000 0.0000 45.000 X3 11.091 10.000 0.0000 36.000 X4 15.417 15.000 0.0000 35.000 Std Dev Y X2 4.0670 10.489 C.V Skewness Ex kurtosis 0.86032 1.2598 0.57478 0.45378 -0.085257 -0.055423 X3 9.7619 0.88017 0.89528 0.19316 X4 9.3956 0.60943 0.12530 -0.73664 Table Correlation coefficients, using the observations - 44 5% critical value (two-tailed) = 0.2973 for n = 44 Y X2 X3 X4 1.0000 0.2442 0.3439 -0.0370 Y 1.0000 -0.2456 0.5105 X2 1.0000 -0.0494 X3 1.0000 X4 Table Variance Inflation Factors Minimum possible value = 1.0 Values > 10.0 may indicate a collinearity problem X2 1.448 X3 1.073 X4 1.364 VIF (j) = / (1 - R(j)^2), where R(j) is the multiple correlation coefficient between variable j and the other independent variables Table Table White's test for heteroskedasticity OLS, using observations 1-44 Dependent variable: uhat^2 coefficient std error t-ratio p-value const −19.2991 21.3285 −0.9048 0.3719 X2 3.19841 2.02129 1.582 0.1228 X3 2.57763 1.39181 1.852 0.0727 * X4 −3.13833 1.48053 −2.120 0.0414 ** sq_X2 −0.0165334 0.0392152 −0.4216 0.6760 X2_X3 −0.0804366 0.0457234 −1.759 0.0875 * X2_X4 −0.0559914 0.0634973 −0.8818 0.3841 sq_X3 −0.0484539 0.0331190 −1.463 0.1526 X3_X4 0.0419238 0.0508004 0.8253 0.4150 sq_X4 0.0993301 0.0560730 Unadjusted R-squared = 0.306368 1.771 0.0855 * Test statistic: TR^2 = 13.480191, with p-value = P(Chi-square(9) > 13.480191) = 0.142054 ... Y: Average money spending on cosmetics per month in 2019 + X2: Average financial support from family per month in 2019 + X3: Average extra earnings per month in 2019 + X4: Average cost of living... money spending on cosmetics per month in 2019 + X2: Average financial support from family per month in 2019 + X3: Average extra earnings per month in 2019 + X4: Average cost of living per month (Food,... three factors we have shown, other factors affect to average spending on cosmetics per month They increase average spending on cosmetics per month about 2000 VND + β2 = 0.19 It means that when average