ANALYSIS OF PURCHASING DECISIONS FOR ADIDAS SPORTSWEAR BASED ON CELEBRITY ENDORSERS AND BRAND IMAGE

The purpose of this study was to determine and analyze the influence of Celebrity Endorser and Brand Image on the Purchasing Decision Adidas Sportswear at Students of the Faculty of Economics and Business, University of Sumatera Utara and also to find out and analyze the most dominant factors affecting purchasing decision. This research was conducted at the Students of the Faculty of Economics and Business, University of Sumatera Utara. The population in this study were students of the Faculty of Economics and Business, University of Sumatera Utara. The sampling technique in this study was accidental sampling. The sample in this study is 81 students. The analytical method used is descriptive analysis method and multiple linear regression analysis method. This type of research is associative research and the data used are primary data and secondary data obtained through the study of documentation and a list of questions whose measurements use a Likert scale. Data is processed statistically using the SPSS, namely the t test model, f test and determinant coefficient (R2). The results of this study indicate that simultaneously Celebrity Endorser and Brand Image have a significant effect on Purchasing Decisions. Partially, the Celebrity Endorser and Brand Image have a positive and significant effect on Purchasing Decisions. Celebrity endorsers have the most dominant influence in influencing purchasing decisions.


INTRODUCTION
In the current era of rapidly developing globalization, humans will experience changes, both in the economic, social and cultural fields, as well as consumer behavior patterns in making purchasing decisions for products that suit their tastes, needs, desires and purchasing power. Every company generally wants to succeed in running its business. However, competition in the business world is getting tougher. Increasingly fierce market competition will indirectly affect a company's efforts to maintain market share. Globalization that is happening at this time makes there are no more restrictions in selling products to several countries around the world including Indonesia. Various types of products have entered Indonesia, one of which is sportswear. This is due to the increasing public awareness of the importance of healthy living by exercising for each individual which is marked by the development of sports centers such as gym¸ futsal fields, jogging tracks, and so on which support people to live healthier lives.
Sport has now become an important requirement for today's modern individuals because exercising will make the body healthier and reduce the risk of various diseases. Free time that is there should be used for exercise. Types of sports that are often carried out by Indonesian people today such as; playing futsal, soccer, playing basketball, and others, of course, requires sports clothing as a tool to support these activities with sports clothing that is comfortable to use. Sport as a need is seen by companies that produce sportswear as a suitable market share to market their products. Competitive competition is shown by the various choices of sportswear available in the market which leads consumers to be more selective in making purchases. Several large companies such as Adidas, Nike, Puma, and Reebok are companies that experience tough competition in this industry. These companies are required to be able to meet the needs and desires of consumers in order to be able to compete with one another. Companies that are unable to meet the needs and desires of consumers will naturally lose in this competition. Consumers themselves are the company's main key in achieving high profits and market share, so it is not surprising that these companies are competing to provide satisfaction and the best quality through the products offered. This market share is created because of the satisfaction and trust that is created due to the effects of using these sportswear. Kotler & Armstrong (2008) define purchasing decisions as a process in which consumers recognize the problem, seek information about a particular product or brand and evaluate how well each of these alternatives can solve the problem which then leads to a purchasing decision. If a product is good in the eyes of consumers, consumers will make purchases of that product. Factors that influence purchasing decisions for a product include celebrity endorser, and brand image. The function of these variables is as a benchmark to what extent the effectiveness of the variables that influence the purchasing decision later. In this study, researchers were interested in seeing that the object under study was students, especially students of the Faculty of Economics and Business, University of Sumatera Utara, who almost did lecture activities every day. They need a moment to relieve fatigue by doing sports activities, good for health and reduce stress due to college assignments. Because if you look at the last few years, there have been many activities held by student organizations such as Fun Futsal and Basketball among students aimed at establishing cohesiveness among students. These activities certainly require supporting elements, namely sports clothing. According to the observations of researchers, sportswear that is often used is Adidas and Nike. Adidas sportswear not only offers good sportswear but also gives the user an impression of confidence. Adidas sportswear always offers good designs to support its users in exercising. This is the basis for why research was conducted at the Faculty of Economics and Business, University of Sumatera Utara.
The questions in this study are (i) Does Celebrity Endorser and Brand Image simultaneously significantly effect the purchasing decision of Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara? (ii) Does Celebrity Endorser have a partially positive and significant effect on purchasing decisions for Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara? (iii) Does Brand Image have a partially positive and significant effect on the purchasing decision of Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara? In line with the research questions, two research objectives were answered. The two research objectives are: (i) To find out and analyze the effect of celebrity endorser and brand image on purchasing decisions for Adidas sportswear for students of the Faculty of Economics and Business, University of Sumatera Utara. (ii) To find out and analyze the effect of Celebrity Endorsers on purchasing decisions for Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara. (iii) To find out and analyze the effect of Brand Image on purchasing decisions for Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara.

LITERATURE REVIEW Celebrity Endorser
According to Shimp (2010) celebrity endorsers are commercials, television, actors, films, famous athletes, to individuals who have died, who can influence consumer attitudes and behavior on the products they advertise. In advertising and other promotional activities, the use of message sources to say or show advertising messages can be done by selecting messengers who are considered to have an effect on the effectiveness of advertising communications. In this case, celebrity endorsers can be used as a tool for written or spoken statements about a product (goods and services). According to Shimp (2010) the five attributes of a celebrity endorser are explained as follows: 1. Trustworthiness, defined as the confidence and trust possessed by the sender of the message, so that the person can be trusted. 2. Expertise, defined as the expertise possessed by the sender of the message related to the brand being advertised.
3. Physical attractiveness, defined as the celebrity's physical attractiveness in terms of beauty, good looks, gallantry, and so on. 4. Respect (respect), defined as a quality that becomes a person's praise or appreciation because of the achievement or intelligence of a celebrity. 5. Similarity, defined as the degree to which celebrities are considered to have similarities with audiences, for example age, gender, ethnicity, and so on.
In choosing a celebrity endorser, many people must know it, because it can influence the positive image that reflects the product so that choosing the right celebrity endorser in advertising is very important.

Brand Image
According to Kotler & Keller (2012) brand image is the perception and belief held by consumers, which is reflected or embedded in the minds and memories of a consumer himself. This perception can be formed from information or past experiences of consumers towards the brand. According to Tjiptono (2009) Brand image, which is a description of consumer associations and beliefs about certain brands. For this reason, the development of a brand image, especially a positive image, is one of the important things. Because without a strong and positive image, it is very difficult for companies to attract new customers and retain existing ones, and at the same time ask them to pay a high price. According to Aaker (1997) there are four main things that must be considered in forming a brand, namely: 1. Recognition, the level of recognition of a brand (brand) by consumers. 2. Reputattion, a level or status that is high enough for a brand (brand) because it is more proven to have a good "track record". 3. Affinity, a kind of emotional relationship that arises between a brand (brand) and its consumers. 4. Brand loyalty, a measure of customer loyalty to a brand.

Purchasing Decision
Kotler & Armstrong (2008) define purchasing decisions as a process in which consumers recognize the problem, seek information about a particular product or brand and evaluate how well each of these alternatives can solve the problem which then leads to a purchasing decision. In purchasing decisions, generally there are 5 (five) kinds of roles that a person can perform. The five roles include (Kotler & Armstrong, 2008): 1. Initiator (Initiator) The person who first recognizes a desire or need that has not been met and proposes an idea to buy a particular good or service.

Influencers
People who provide views, advice, or opinions that can help with purchasing decisions.

Decision maker (Decider)
The person who determines the buying decision, whether to buy, what to buy, how to buy, or where to buy it.

Buyer (Buyer)
The person making the actual purchase.

Users (Users)
People who consume or use the product that has been purchased.

RESEARCH METHOD
This type of research is associative research. According to Sugiyono (2010). Associative research is research that aims to determine the relationship between two or more variables. The variables connected in this study are independent variables, namely celebrity endorser variables (X1) and brand image (X2), as well as the dependent variable, namely purchasing decisions (Y). The measurement of the indicators of this research variable uses a Likert Scale, namely by compiling questions or statements in which each item is given a range score on the Likert Scale. The population in this study were students of the Faculty of Economics and Business, University of Sumatera Utara who were still actively studying. The sampling technique in this study was that the sample was taken using a non-probability sample design using accidental sampling technique, namely the sampling technique based on coincidence, that is, anyone who is accidentally met by the researcher and has the appropriate criteria will be used as a sample. The criteria for selecting the sample were students of the Faculty of Economics and Business, University of Sumatera Utara who were still actively studying and who had bought and used Adidas brand sportswear.
According to Supramono & Haryanto (2012) to determine the number of samples from an unknown population, you can use the formula: n=Z^2 α ( (P)(q))/((d^2 ) ) Information: n = number of samples Zα = normal standard value whose magnitude depends on α If α = 0.01 Zα = 2.58 If α = 0.05 Zα = 1.96 If α = 0.10 Zα = 1.67 p = estimator of the proportion of the population that meets the sample criteria q = the proportion of the population that meets the sample criteria (1-p) d = deviation tolerable (10 %) Based on the results of a survey conducted by researchers on 30 students of the Faculty of Economics and Business, University of Sumatera Utara, it was found that 21 people had bought and used Adidas sportswear (70%) p= 0.70 , and 9 other people (30%) q= 0. 30 have never bought and used Adidas sportswear with α 5% (0.05) and d 10% (0.1). By using this formula it can produce the number of samples as follows: n =(1,96)^2 (0,70)(0,30)/〖0,1〗^2 = 80.6736 = 81 people Based on the results of these calculations, the number of respondents who will be sampled in this study is rounded up to 81 people. The data analysis technique in this study is descriptive statistical analysis and multiple linear regression analysis using SPSS software.   Table 2, the equation can be described as follows: The Celebrity Endorser variable (X1) partially has a significant effect on the Purchasing Decision (Y), this can be seen from the significant value (0.020) <0.05. Brand Image Variable (X2) partially has a significant effect on Purchasing Decision (Y) this can be seen from the significant value (0.000) <0.05.  Table 3, it can be seen that the Adjusted R Square value of 0.423 means that 42.3 percent of the purchasing decision factors (Y) can be explained by celebrity endorsers (X1) and brand image (X2). While the remaining 57.7 percent is explained by other factors not examined in this study.

The effect of celebrity endorser on purchasing decisions
The results of this study indicate that the coefficient X2 = 0.279. This shows that the variable Celebrity Endorser (X2) has a positive effect on the Purchasing Decision of Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara. If the Celebrity Endorser variable (X2) increases by one unit, the Purchasing Decision will increase by 0.279. Partially, the Celebrity Endorser variable has a partial positive and significant effect on purchasing decisions. This can be seen from the significant value (0.020) <0.05. The results of the study show that recognizing celebrity endorsers, the ability of celebrity endorsers to attract consumer confidence and celebrity endorsers having the expertise to convey messages can influence purchasing decisions. From the distribution of respondents' answers to the Celebrity endorser variable, it can be seen that 56 (69.1 percent) of respondents agreed that the celebrity endorser used in Adidas sportswear advertisements is known by the public. 55 (67.9 percent) of respondents stated that they agreed that celebrity endorsers in Adidas sportswear advertisements had the ability to attract consumer confidence to buy Adidas sportswear products. 55 (67.9 percent) of respondents stated that they agreed that celebrity endorsers in Adidas sportswear advertisements had the expertise to convey messages to their consumers.
The use of celebrities as advertising stars is believed to have its own charm, namely having the advantage of publicity and the power to get attention from consumers. This is in accordance with what was stated by the expert. According to Shimp (2010) celebrity endorsers are advertisement stars, television, actors, films, famous athletes, to individuals who have died, who can influence consumer attitudes and behavior on the products they advertise. Celebrity endorsers are one of the important factors that consumers see in making purchase. Some consumers buy Adidas sportswear because the celebrities used by Adidas are consumers' idols. This is the reason consumers buy Adidas sportswear. Celebrities also have the power to be used as a tool to persuade, seduce, and influence target consumers with their fame or popularity. By utilizing this fame, it is hoped that it can attract consumers to make purchases of advertised products. This is in line with research conducted by Febriyanti and Wahyuati (2016) and Yanuar (2016) which states that celebrity endorsers have a positive and significant effect on purchasing decisions.

The Effect of Brand Image on Purchasing Decisions
The results of this study indicate that the coefficient X3 = 0.527. This indicates that the Brand Image variable (X3) has a positive effect on the Purchasing Decision of Adidas Sportswear for Students of the Faculty of Economics and Business, University of Sumatera Utara. If the Brand Image variable (X3) increases by one unit, the Purchasing Decision will increase by 0.527. Partially, the brand image variable has a positive and significant effect on purchasing decisions. This can be seen from the significant value (0.000) <0.05. The results of the study show that giving confidence when wearing Adidas sportswear, knowing the Adidas brand than other brands and Adidas having products that are durable compared to other brands can influence purchasing decisions. From the distribution of respondents' answers for the Brand Image variable, it can be seen that 56 (69.1 percent) of respondents agreed that wearing adidas sportswear gives them confidence when wearing Adidas sportswear. 44 (54.3 percent) respondents agreed indicating that they were sure that respondents were more familiar with the Adidas brand than other brands. 48 (56.8 percent) of respondents stated that they agreed that Adidas has a durable product compared to other brands.
A strong brand image can provide several main advantages for a company, one of which will create a competitive advantage. Products that have a good brand image tend to be more easily accepted by consumers. Customer perceptions of a good brand image can be considered by consumers in making purchases. So that brand image is a variable that influences consumer perceptions to buy products. This is in accordance with what was stated by the expert. According to Kotler & Keller (2012) brand image is the perception and belief held by consumers, which is reflected or embedded in the minds and memories of a consumer himself. This perception can be formed from information or past experiences of consumers towards the brand. In this case, the Adidas brand image in society is positive, so many people like and choose it. Many people also consider that Adidas has a fairly expensive selling price, even so, the satisfaction that is owned by the buyer is channeled so that many consumers choose it. Students of the Faculty of Economics and Business, University of Sumatera Utara choose Adidas Sportswear due to various considerations such as good quality clothes, attractive models and consumers who are satisfied with their use. With a good brand image of Adidas Sportswear, it can improve consumer purchasing decisions. This is in line with research conducted by Reven &/ Ferdinand (2017), Aldin (2017), Kumalasari (2016), Yanuar (2016), Mawarni (2016) and Asshiddieqi (2012) which states that Brand Image has a positive and significant effect on Buying decision.

CONCLUSION
Based on the results of data analysis, it can be concluded that celebrity endorsers are also an indicator that has a positive and significant effect on purchasing decisions. In order to increase purchasing decisions, celebrity endorsers used in a product advertisement must be able to attract people who see the advertisement to be interested. In order to make it easier to attract people to see advertisements, researchers suggest that Adidas use Celebrity Endorsers who have a large idol (fan) base, have high popularity and credibility and are liked by many consumers so that consumers will be interested in seeing advertisements. Besides that, it also forms a good image in the minds of consumers for the product and makes purchasing decisions. Brand Image is one of the indicators that influence Purchasing Decisions. In terms of improving purchasing decisions, researchers suggest for Adidas to be more active in making announcements of the company's successes and achievements in public and always doing consumer-oriented marketing. Adidas must be able to provide information about their products, both old and new, and easy access to information through their website. That way Adidas has been able to improve their brand image. From the limitations of previous research, it is hoped that future research will use this research as a basis for further research and add independent variables besides Celebrity Endorser and Brand Image which of course can effect the dependent variable, Purchasing Decision to further complement this research because there are still variables other independent variables such as lifestyle, beliefs, consumer attitudes and others that might influence purchasing decisions.