Job satisfaction during expatriation.
Employee satisfaction and motivation have an important influence on individual employees and the performance of companies. In international business and marketing, where expatriates play important roles, regional cultures and institutional factors impact their satisfaction and motivation. This chapter aims to find out what kind of regional cultures and institutions have an impact on employee satisfaction and motivation in multinational corporations (MNCs), using theoretical analysis and the results from around 100 Japanese expatriates’ questionnaires. It was possible to find the satisfaction and motivation-related characteristics of expatriates in MNCs from the results of their interviews and the questionnaire survey, which indicated that Japanese expatriates working in the USA, Singapore, and Indonesia had a higher job satisfaction degree than those working in cultural regions, such as China, Taiwan, and Australia. Moreover, the results showed that compared with other industries, in the sales and marketing industry, the Japanese expatriates had the lowest satisfaction degree after repatriation, although their satisfaction degree was higher during expatriation and after a career change. The reasons relating to regional cultures and institutions, and some methods and human resource management practices in international marketing and trading that were analyzed are expected to raise expatriates’ satisfaction and motivation.
Globalization has created a lot of opportunities and challenges in the world economy, especially for trade and marketing enterprises, as well as employees. The performance of multinational corporations (MNCs) and trading industries are significantly impacted by culture, institutions, as well as economic and political factors. Further, as internal impact factors, employees’ motivation and job satisfaction also have a crucial influence on the accomplishments of MNCs and the trading and marketing industry.
Expatriates play important roles in globalization and international marketing and trading. The term “expatriates” refers to home country nationals, who are assigned from headquarters to work in overseas subsidiaries for 3–5 years. After their expatriation assignment, they can repatriate to their headquarters, and utilize their experiences and knowledge from their overseas assignment . When they work overseas, they have to adapt to the local culture and institutional environment.
Expatriates are considered as special and important employees in MNCs. Japanese MNCs mainly promote localization in Europe and America. However, in overseas subsidiaries of Japanese MNCs in Asian countries, Japanese expatriates from headquarters still play important roles, instead of local employees, even though localization is also conducted gradually in these subsidiaries. However, the job satisfaction and motivation of these Japanese expatriates needs to be raised, given that, some of them quit during the expatriation period without repatriating to headquarters, as scheduled. This brings significant damage to both the overseas subsidiaries and headquarters of the Japanese MNCs.
Employee satisfaction and motivation have an important influence on individual employees and the performance of companies. In the international marketing and trading business, expatriates play important roles. Previous literature indicates that expatriates’ satisfaction and motivation will be impacted by regional cultures and institutional factors. This chapter addresses the research gaps relating to the kinds of regional cultures and institutions that have an impact on expatriates’ satisfaction and motivation in MNCs. The results obtained from the interviews and questionnaire survey, were able to reveal the characteristics related to satisfaction and motivation of Japanese expatriates in MNCs. Furthermore, reasons related to regional culture and institutional issues, and some methods and human resource management practices in international business that were analyzed, are expected to raise employee satisfaction and motivation. Some topics for future research are also discussed in the final part of this chapter.
2. Previous literature
Culture is considered a central concept in anthropology, encompassing the range of phenomena that are transmitted through social learning in human societies, as stated in Wikipedia .
Moreover, culture is an umbrella term which encompasses the social behavior and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups .
Japan is a country with a long history and a unique culture. When Japanese expatriates work overseas, culture and the institutional environment are very important for them. Japan’s traditional employment style is career employment, with a relational psychological contract between the employees and employers being common, along with collectivism in their high context society . However, in recent years, performance-based pay system has been introduced in Japan. Meanwhile, in some cases, the psychological contract is also changing from relational to transactional.
It has been stated  that context refers to the environment, in which people carried out their communications, considering society, psychology, timing, etc. According to Ferraro , high to low context levels exist in Japan, China, Arabia, Greece, Spain, Italy, English, France, America, and Germany. Hence, people in various cultures and context environments carry out communications in different ways. Especially in advanced countries and emerging economies, management approaches and lifestyles differ greatly. In high context culture environments, people share detailed information with group members more frequently and implicitly. On the contrary, in low context cultural countries or regions, people talk more frankly with each other.
Other scholars have pointed out that leadership could not transcend cultures. Leadership styles in the USA and Middle East are significantly different. Managers in the United Arab Emirates are found to be less transformational and more passive than managers in the USA and Europe . Differences in leadership styles in various cultural organizations cause frustration and conflict among managers .
Organizations also have their own company cultures. A strong company culture helps to reduce management and monitoring costs, and also serves as a good reference of a behavior model. It facilitates information transference and raises a company’s work efficiency. It even has an influence on organization transformation. However, a company’s culture will be influenced by the culture of the country in which it is located, and its leadership style. Therefore, cultures in companies or countries have significant impact on the performance of both employees and organizations.
Institutions have been described as “integrated systems of rules that structure social interactions” .
Moreover, institutions can refer to mechanisms which govern the behavior of a set of individuals within a given community, and are also identified with a social purpose, transcending individuals and intentions, by mediating the rules that govern living behavior .
2.3 Institutions and governance/management
From the perspective of new institutional economics, it has been stated  that institutions would change, along with the economy and environment. In different regions, there are various institutions and cultures. These theories are implemented in business strategy, corporate governance, and property. Governance has been divided into two kinds: relational and hierarchical governance . In developing countries or regions, where institutions or laws are not that advanced, it is easier to control people’s behaviors through personal relationship networks, the culture of a company or country, or societal ethics, which is called relational governance. On the contrary, in advanced countries or regions, where institutions and managements are developed to a relatively high extent, people can be controlled by rules, manuals, or institutions at a high level, which is called hierarchical governance.
Hence, in this globalized world, businesses freely advance into many countries and regions across the world. However, we cannot ignore the cultural and institutional characteristics of every country or region since invisible culture walls exist between different countries. Hence, the important concept of “semi-globalization” exists . When actively promoting a trading or marketing business in foreign countries, it is also necessary to respect the differences in culture and institutional environments between host countries and the headquarter country.
In 1970, Maslow  proposed the 5 levels of hierarchy of needs theory. These basic needs of human beings have a significant relationship with employees’ motivation.
Motivation—derived from the word “motive” or a need that requires satisfaction—is a reason for actions, willingness, and goals. These needs, wants or desires may be acquired through the influence of culture, society, lifestyle, or may be generally innate, as has been stated in Wikipedia . Individuals’ motivation could be inspired by outside forces (extrinsic motivation) , or those within individuals because it is naturally satisfying to them (intrinsic motivation) .
In a company, there are many kinds of extrinsic motivation, such as compensation, bonus, promotions, expanded responsibility, awards, opportunity of on-job or off job training, travelling, stock options, and related qualifications. Additionally, emotions have an influence on motivation, and positive emotions can also raise one’s motivation . Hence, favorable personal relationship networks and workplace environments are also important for employees’ motivation and job satisfaction. Such extrinsic motivators can also be called incentives to some extent. The importance of intrinsic and extrinsic motivation in business has been emphasized .
An incentive is something that motivates or drives one to do something or behave in a certain way . There are two type of incentives—intrinsic and extrinsic—that affect human decision making, as stated in Wikipedia . Intrinsic incentives motivate persons to do something out of their own self-interest or desires, without any outside pressures or promised rewards , whereas extrinsic incentives are motivated by rewards, such as an increase in pay for achieving a certain result; or avoiding punishments such as disciplinary action, or criticism as a result of not doing something [20, 22].
The expectancy theory  posits that an individual’s motivation is a function of two factors: (i) expectancy about the relationship between the effort and a particular outcome and (ii) the valence of that outcome. Monetary incentives like compensation have valence for a variety of reasons. Therefore, employees’ motivation and subsequent efforts are significantly high if compensation is based on performance.
It has been stated that items that motivate and incentivize expatriates, include providing effective programs before or during expatriation, reasonable selection and promotions, fare performance evaluations, attractive compensation during expatriation, full consideration or correspondence for their families, career up or career design considerations, etc. . This is because these items comprise important contents of psychological contracts between expatriates and their headquarters, which expatriates expect their headquarters to conscientiously fulfill.
3. Research methods
To find the difference in expatriates’ satisfaction degree between various industries (sales and marketing, manufacturing, service, etc.), a questionnaire survey was conducted in 2015, which revealed distinct characteristics of various regions or countries such as USA, Singapore, Indonesia, China, Australia, etc. The questionnaires were distributed to around 100 Japanese expatriates, who were required to answer satisfaction and motivation-related questions pertaining to their last expatriation of more than a year’s duration. The expatriates were older than 25 years, their job types included civil servants, company employees, freelancers, etc., and their education qualifications ranged from high school graduates to doctorates (see Tables 1–3).
|Q12 Comment on your job satisfaction during the expatriation|
|All||Very satisfied||A little satisfied||I can’t say||Not very satisfied||Not satisfied||Average|
|Age||25 ∼ 29||13||15.4||76.9||7.7||0.0||0.0|
|30 ∼ 34||12||0.0||50.0||41.7||8.3||0.0|
|35 ∼ 39||14||14.3||50.0||21.4||7.1||7.1|
|40 ∼ 44||16||25.0||37.5||12.5||18.8||6.3|
|45 ∼ 49||19||26.3||57.9||5.3||10.5||0.0|
|50 ∼ 54||14||28.6||42.9||21.4||0.0||7.1|
|55 ∼ 59||11||0.0||81.8||9.1||0.0||9.1|
|60 and over||4||25.0||50.0||25.0||0.0||0.0|
|Company employee (administrative)||33||15.2||63.6||12.1||9.1||0.0|
|Company employee (technical)||48||22.9||43.8||27.1||4.2||2.1|
|Company employee (other)||19||5.3||68.4||0.0||10.5||15.8|
|Q1 Diploma||High school graduate||19||21.1||42.1||26.3||10.5||0.0|
|Junior college graduate||2||0.0||100.0||0.0||0.0||0.0|
|Q3 Your rank in the latest expatriation longer than 1 year||Ordinary Staff||27||11.1||51.9||29.6||7.4||0.0|
|Q5 Your work in the latest expatriation longer than 1 year||Technology||36||16.7||55.6||19.4||5.6||2.8||3.78|
|Sales & Marketing||13||30.8||46.2||0.0||15.4||7.7||3.77|
|Q2 Your current rank||Ordinary Staff||25||12.0||48.0||32.0||8.0||0.0|
|Q4 Your current job type||Technology||41||17.1||56.1||17.1||7.3||2.4|
|Sales & Marketing||15||26.7||60.0||0.0||6.7||6.7|
|Q7 The industry type of the latest expatriation longer than 1 year||Manufacturing||54||20.4||48.1||22.2||7.4||1.9||3.78|
|Sales & Marketing||13||30.8||53.8||0.0||7.7||7.7||3.92|
|Age||25 ∼ 29||7||0.0||85.7||0.0||0.0||14.3|
|30 ∼ 34||10||0.0||30.0||50.0||10.0||10.0|
|35 ∼ 39||13||7.7||46.2||15.4||0.0||30.8|
|40 ∼ 44||15||13.3||46.7||20.0||20.0||0.0|
|45 ∼ 49||18||5.6||38.9||33.3||11.1||11.1|
|50 ∼ 54||14||21.4||42.9||21.4||14.3||0.0|
|55 ∼ 59||10||0.0||80.0||20.0||0.0||0.0|
|60 and over||4||25.0||25.0||50.0||0.0||0.0|
|Q1 Diploma||High school graduate||17||5.9||52.9||35.3||5.9||0.0|
|Junior college graduate||1||100.0||0.0||0.0||0.0||0.0|
|Q3 Your rank in the latest expatriation longer than 1 year||Ordinary Staff||21||0.0||57.1||28.6||4.8||9.5|
|Q5 Your work in the latest expatriation longer than 1 year||Technology||31||9.7||54.8||25.8||0.0||9.7||3.55|
|Sales & Marketing||12||8.3||33.3||33.3||8.3||16.7||3.08|
|Q2 Your current rank||Ordinary Staff||18||0.0||50.0||33.3||5.6||11.1|
|Q4 Your current job type||Technology||34||8.8||55.9||23.5||2.9||8.8|
|Sales & Marketing||14||7.1||42.9||28.6||7.1||14.3|
|Q7 The industry type of the latest expatriation longer than 1 year||Manufacturing||46||10.9||47.8||23.9||8.7||8.7||3.43|
|Sales & Marketing||12||8.3||50.0||16.7||8.3||16.7||3.25|
|Q30 Comment on your job satisfaction after your career change|
|All||Very satisfied||A little satisfied||I can’t say||Not very satisfied||Not satisfied||Average|
|Age||25 ∼ 29||6||16.7||66.7||16.7||0.0||0.0|
|30 ∼ 34||1||0.0||100.0||0.0||0.0||0.0|
|35 ∼ 39||1||0.0||100.0||0.0||0.0||0.0|
|40 ∼ 44||1||0.0||0.0||0.0||100.0||0.0|
|45 ∼ 49||1||0.0||100.0||0.0||0.0||0.0|
|Job||Company employee (administrative)||4||0.0||50.0||25.0||25.0||0.0|
|Company employee (technical)||3||0.0||100.0||0.0||0.0||0.0|
|Company employee (other)||3||33.3||66.7||0.0||0.0||0.0|
|Q1 Diploma||High school graduate||2||0.0||100.0||0.0||0.0||0.0|
|Junior college graduate||1||0.0||100.0||0.0||0.0||0.0|
|Q3 Your rank in the latest expatriation longer than 1 year||Ordinary Staff||6||16.7||50.0||16.7||16.7||0.0|
|Q5 Your work in the latest expatriation longer than 1 year||Technology||3||0.0||100.0||0.0||0.0||0.0||4.00|
|Sales & Marketing||1||0.0||0.0||0.0||100.0||0.0||2.00|
|Q2 Your current rank||Ordinary Staff||6||16.7||50.0||16.7||16.7||0.0|
|Q4 Your current job type||Technology||5||20.0||60.0||0.0||20.0||0.0|
|Sales & Marketing||1||0.0||100.0||0.0||0.0||0.0|
|Q7 The industry type of the latest expatriation longer than 1 year||Manufacturing||6||16.7||66.7||0.0||16.7||0.0||3.83|
|Sales & Marketing||1||0.0||100.0||0.0||0.0||0.0||4.00|
4. Results of the questionnaire survey
Based on the aforementioned questionnaire survey, this section summarizes its results based on categories, such as industries, job types, and regions.
4.1 Results category by industry and the sales & marketing job type
The average value of expatriates’ satisfaction degree in the sales and marketing industry were 3.92 (during expatriation), 3.25 (after repatriation), and 4 (after a career change) (see Tables 1–3). As compared with other industries, for sales and marketing, the satisfaction degree after repatriation was the lowest at 3.25, but during expatriation and after a career change it was higher than that of other industries.
Conversely, when expatriates had worked for the government, their satisfaction degree was the highest after repatriation as well as during expatriation. However, their satisfaction degree during expatriation and after a career change were the lowest when they had worked in service industries. Similarly, the satisfaction degree after repatriation was also at a low level, compared with other industries.
These results show that expatriates in sales and marketing, as well as service industries experience more difficulties during expatriation. Thus, they need more incentives to raise and keep their work motivation at a relatively high level. The values in various regions are shown in Table 4.
|Assigned country or region||Number of expatriates||Number of expatriates who turned to another company after expatriation||Satisfaction degree valuesa during expatriation||Satisfaction degree valuesa after repatriation||Satisfaction degree valuesa after a career change|
A comparison of sales and marketing with other job types indicate that while the satisfaction degree during expatriation was relatively high (higher than average), it was the lowest after repatriation or a career change. The reason for this result is also worthy of discussion.
4.2 Results category by region and country
From the perspective of expatriates working overseas in various regions and countries, as shown in Table 4, their working places in this survey mainly included USA, China, Taiwan, Thai, Indonesia, Singapore, Australia, etc. Their average satisfaction degree values were 2.24, 2.6, and 2.2 during expatriation, after repatriation, and after a career change, respectively.
The satisfaction degree was higher than the average levels in the following cases: during expatriation of those in USA, Singapore, and Indonesia; after repatriation of those in USA, Thai, Singapore, and Indonesia; and after a career change of expatriates working in the USA and China during expatriation. Thus, it seems that working in USA, Singapore, and Indonesia creates a higher job satisfaction degree than working in other places.
4.3 Reasons based on industry and the sales and marketing job type
It is necessary to analyze the reason why the satisfaction degree relating to the sales and marketing industry is high during expatriation, while it is the lowest after repatriation. As this industry’s mission is to explore foreign markets, it is easier for it to adapt to overseas environments and new cultures, compared with other industries. Due to its characteristic of being open minded, its satisfaction degree during expatriation is high. Since after repatriation, the objective that needs to be explored changes, expatriates have to adjust the direction of their work, try to acquire knowledge of new products and related fields, and build relationships with new domestic clients. Because of resource peculiarity and culture distance between the host country and parent country, the knowledge, experience, and even local personnel relationship they acquired or built in foreign subsidiary in the host country are not able to be utilized fully any more in the headquarter in parent country sometimes after repatriation. In some cases after repatriation, Japanese expatriates are assigned to positions where work contents are very different with before, which has negative impact on job satisfaction degree and some expatriates quit after repatriation. This can also be considered as a part of the reasons why the satisfaction degree is not low after career change. Usually, people turn to work in companies where their experiences and knowledge can be taken full advantage. If their knowledge and experiences can be used to a relatively high extent, this has positive influence on their job satisfaction degree. Furthermore, they have to once again cope with the culture shock.
In government industries, the work stress is not as heavy as in the sales and marketing or service industries. Their main work is to build relationships with local governments and big companies. Since government expatriates also conduct some surveys in terms of foreign markets and society-related issues, their satisfaction degree is high.
Contrarily, expatriates in the service industry have higher work stress because they have to carefully understand the local culture and customs, and use them correctly and flexibly, so that they are able to explore and retain enough foreign new clients. Their communication and interaction with local clients have a significant influence on their company’s performance.
4.4 Reasons based on regions and countries
This section analyzes the reasons in terms of the characteristics of culture and institutions in different regions and countries. The reasons partly lie in the characteristics—economy, culture, institutions, and history—of these 3 countries: USA, Singapore, and Indonesia, in which, the satisfaction degree of Japanese expatriates is higher.
USA has a long-term trading partnership with Japan—one of its biggest trading partners. It also respects culture building itself and promotes cultural communications with other countries. In past decades, it promoted a lot of cultural products to countries all over the world. Being an immigrant country, its cultural characteristics comprise diversity and openness in populations and regions. Its annual GDP exceeds 60000 dollars per year and it has a good economic environment. In USA, people use data and manuals to manage employees, rather than relationships or personal networks. Thus, it is easy for employees who work hard since they will not have the difficult task of trying to develop skills to build good relationships with supervisors. Hence, Japanese expatriates find it a good place to live and work.
Singapore too, has an open cultural environment, and Japan is one of its biggest trading partners. It is located in Asia and more than 70% of its population are Chinese. It embraces several religions, and with England’s long and important influence on its history, it follows English traditions that contribute to its stable circumstances. It is famous for its cleanliness because of its comfortable weather. Singapore is also a developed country and among the best international financial centers in the world, along with New York, London, and Hongkong. Since its finance and other related rules and institutions are very well organized, it is easy for Japanese expatriates to adapt to its institutional environment.
Indonesia has many nations and is a multicultural country. It has many religions and beautiful places, such as the Bali island, a world-famous place. It also has many kinds of delicious food, which attract many travelers every year. Hence, it is easy for foreigners to live and work in Indonesia, although it is not an advanced country and its weather is a little hot in summer.
In contrast, the satisfaction degree is lower than average in China, Taiwan, and Australia.
China is a multicultural country with a very long history. Its open culture environment and delicious food welcomes foreign investments, companies to establish subsidiaries, and foreigners to work in China. Both the Chinese and Japanese use Chinese characters in their language, which is a commonality between China and Japan. Hence, it is convenient for Japanese expatriates to learn Chinese, adapt to the Chinese lifestyle, and work there. However, it is not an advanced country and its institution and policies for business management as well as other fields still need improvements and innovation. Taiwan is similar to China to some extent in terms of culture. Moreover, Japan is a country with a high context communication environment, where people express their opinions more implicitly. This kind of communication style of Japanese expatriates needs better understanding and cooperation of local Chinese employees.
In China, economic reforms and opening-up that have been prevalent for more than 40 years, have brought about a lot of wonderful changes to many facets of China. However, its management style and communication-related issues have existed during the whole developing process. In China, relational governance is still the main style. Contrarily, Japan is an advanced and developed country, where hierarchical governance is implemented to a large extent. Rules and law are set in detail in terms of a lot of facets of society and business. This is another big difference between Japan and China.
Australia is at a high World Happiness Index ranking. It also has several religions and a multicultural environment, along with beautiful mountains and rivers for people to enjoy. Its economic situation is also stable. Therefore, it is a comfortable place, where foreigners find it easy to work. Yet, expatriates have a lower than average satisfaction degree. The reason is worthy of discussion. It has been stated that the methods of performance appraisal of Australian expatriates in Singapore and Singaporean expatriates in Australia are greatly different in terms of performance against set indicators, rating of specific competencies, set and evaluate personal goals, management by objectives, informal discussion with superior, et. . Previous literature also indicates that Japanese expatriate managers rely on cultural mediators more . The themes of cultural mediators’ features refer to reliance on a third party individual, role of “go-betweens”, and bicultural characteristics. Other scholars state that becoming mutual sunao (accepting) is crucial in trust and intercultural communication based on research on Japanese expatriate managers and Australian supervisors . These conclusions provide hint to consider the reason from intercultural communication and performance evaluation system of local subsidiaries.
5. Implications and discussion
To raise the satisfaction degree of the service industry as well as the sales and marketing industry, it is better for the headquarters to undertake adequate foreign culture training and marketing surveys prior to assigning expatriates to work overseas since it helps them to adapt to the local work environment faster and also raises their work performance. Additionally, it is useful for reducing their work stress during expatriation, and facilitates the building of smooth personal relationship networks, all of which, contribute to enhancing expatriates’ skills and task achievements, which lead to higher job satisfaction. Another approach to raise the satisfaction degree after repatriation is to prepare fitful positions for expatriates and create better opportunity to utilize their experience, knowledge, and network with local government or employees. This has positive effect on their retention rate and prevent them from turning over after repatriation.
To raise the levels of motivation and satisfaction in China and Taiwan, helpful measures could be higher compensation, better work conditions, welfare, consideration for families, language support during expatriation, promotion or expanded responsibility after repatriation, etc. In parallel, China’s vast external environment—companies, institutions, business customs, commercial practices, and management systems—are in dire need of urgent innovation. While the Chinese MNCs have been progressively increasing in recent years, their management and business styles still need to be internationalized. If their management styles could be changed from relational governance to hierarchic governance, it would be easier for Japanese expatriates to adapt to their work and life in Chinese subsidiaries, which would help in increasing their motivation and job satisfaction.
To raise the satisfaction degree in Australia, several measures can be considered. Better trust relationship and intercultural communication environment will contribute to work performance and satisfaction degree. Mutual acceptingness plays important role in building this work place environment. Effective evaluation system is also important for expatriates in Australia. Hence, human resource managers could pay more attention and offer more effort on this facet. As one of the reasons that causes the low satisfaction degree during expatriation is the long distance between Japan and Australia, the headquarters could provide more free flights for expatriates to travel between these two countries for private purposes.
Additionally, not only is there a need to respect the cultures of these countries or regions, but it is also necessary to pay heed to their corporate cultures. Countries’ cultures have an impact on their corporate cultures. However, every company has its own unique history, development path, leaders, and leadership styles which comprise their company’s corporate culture. Thus, foreign expatriates also need to understand corporate cultures, especially in emerging countries, and adapt to them. Some other factors regarding society, politics, and international relationship are also needed to be considered.
This chapter reviews the theories on institutions, cultures, motivation, and incentives. Based on a combination of a comparative analysis of these theories and the questionnaire survey’s results, the reasons were established for different characteristics in various cultures, countries, and industries, including sales and marketing, manufacturing, and service, etc. Additionally, to raise the satisfaction and motivation levels of expatriates in Japanese MNCs, institutional improvements need to be implemented more thoroughly in local governments, along with respecting and understanding diverse cultures.
If we have more equally distributed samples, a valuable issue that needs to be further discussed is cross tabulation to check the relationship between job types and regions. For this, future research could collect additional and better data so that the reasons and impact factors for satisfaction degree can be analyzed more thoroughly.
This research is mainly based on data from expatriates in Japanese MNCs. Hence, how to apply the related conclusions to other cultural environments and industries is still an important issue. To confirm this conclusion or expand the direction of this research, future research could also obtain data from other countries. Interviews with expatriates and local employees is also a helpful approach as a case study to confirm the proposals and analyze the reasons in this chapter.
Conflict of interest
The author declares no conflict of interest.