Does US-China Trade War Matter on ASEAN Stock Market: Event-study Approach

The trade war between the US and China by imposing tariffs has the potential to affect global financial stability. As the largest economy in the world, the US and China had been trading goods and services globally. Then, when these countries have retaliated, the tariff war will affect the global supply chain, international trade, economy, and the stock market. This research examined the effect of the US-China trade war on ASEAN stock prices using an event-study approach. The result shows that the ASEAN stock market has positive abnormal returns during pre-event period (12%). In contrast, ASEAN stock markets shifted to negative abnormal return (-7.4%) in the short-term window, indicating that the stock market is efficient. Stock price reflects the information from the market quickly. However, the impact of the trade war on the ASEAN stock market is insignificant.


Introduction
The trade war between America and China creates global economic uncertainty. This economic uncertainty is reflected in several international financial institutions that revised economic growth. The World Bank lowered its forecast for global economic growth in 2019 to 2.6 percent, down 0.3 percent from the initial prediction of 2.9 percent. Whereas the International Monetary Fund (IMF) predicts that the world economy will only grow 3 percent in 2019, experiencing a slow growth since the global financial crisis in 2009. Trade deficits experienced by America triggers trade conflicts between the two countries with the largest economy in the world. According to Carvalho et al (2019) America experienced a trade balance deficit against many countries, especially China. In 2017, the US trade deficit against China was $ 375 billion, or 42 percent of the total US trade deficit of $ 861 billion. The high US trade deficit prompted President Donald Trump to conduct an investigation that led to the decision to increase import tariffs on Chinese products on March 22, 2018, marked by a presidential referendum. Tariff on imported products from China was increased to 25 percent with a value of more than $ 50 billion. After that, China responded by increasing tariffs on American products, as well as being the start of a trade war between America and China (Breuss & Christen, 2019;Chang et al, 2019). Also, according to Kwan (2020) the United States also restricted technology transfer to China and the business activities of several technology companies from China, such as Huawei.
The trade war between America and China caused not only economic losses for the two countries (Sabala and Devadoss, 2019), but also had direct and indirect impacts on the economies in other countries. The direct impact of the trade war has led to a decline in international trade activities (Bolen and Romagosa, 2018), whereas transactions between countries are essential resources for creating prosperity (Jean et al, 2018). Furthermore, the direct impact of trade war can also create unemployment (Jiming and Posen, 2019). While the indirect impact of the trade war caused the weakening of economic performance in Canada (Charbonneau, 2019), the decline in commodity exports in South Africa (Lemmer, 2019), the decline in exports of solar energy in Malaysia (Yean et al, 2019) and detrimental to the car and spare parts sales in Japan and the European Union (Abiad et al, 2018).
American and Chinese trade conflicts, in the long run, have the potential to reduce investor confidence, affecting the economy in Europe and the world (Gunnella and Quaglietti, 2019). This distrust can be detected from American long-term bond yields, which are lower than short-term bond yields (Sebgroup, 2019). Besides, according to Yefremov (2018) the low economic growth in China will reduce demand for raw materials from other countries, which will have an impact on developing countries such as Taiwan, Singapore, Vietnam, Thailand, and Malaysia, because of the role of the two countries in the global supply chain. According to Evans (2019), in a trade war, all countries could suffer losses. Each increase in tariff of 10 percent from both two countries (America and China) will reduce economic growth by almost 2 percent and can reach 3 percent after two years (Berthou et al, 2018).
Furthermore, the effects of American and Chinese trade war can disrupt global economic stability (Chong and Li, 2019;Steinbock, 2018) and shock the financial markets (Meltzer and Shenai, 2019). According to Huang et al (2018) the stock prices of Chinese and American companies affiliated in trade between the two countries experienced a decline during the announcement of the trade war on March 22, 2018. Transmission of uncertain economic conditions can be recognized from the spill-over effect that occurs when there is a financial world shock (Kim et al, 2015). Source : World Bank (2019) The market capitalization of ASEAN countries has decreased during the period of the trade war, except Vietnam. Overall, the ASEAN capital market lost $ 264 billion (-10%). The highest decline in market capitalization value was Singapore and Malaysia's capital markets, which were -13% while Vietnam's capital market has experienced a growth in market capitalization of $ 7 billion, or growing 7% in 2018.
In this paper, researcher tries to look at the effects of the American and Chinese trade wars on the ASEAN capital market. ASEAN countries, especially those that already have capital markets, including Indonesia, Malaysia, Singapore, Thailand, the Philippines, and Vietnam, are the subjects of research. The ASEAN capital market was selected with several considerations, including: 1) the market capitalization ratio of ASEAN countries to the global market capitalization is 4 percent in 2018, this number grew by 1 percent compared to the contribution of the ASEAN capital market to the global capital market in 2017, 3 percent; 2) the ASEAN capital market also has significant potential based on increasing population and relatively stable economic growth; 3) the number of small and mediumsized companies in ASEAN countries that have the potential to conduct an Initial Public Offering (IPO).
This research contributes to describe the capital market response of ASEAN countries when there is a trade conflict between the United States and China. The results of this study can comprehend the literature as well as a source of information for investors and investment managers to diversify their portfolios in order to create optimal returns and risk mitigation from global economic uncertainty triggered by trade war between the two countries with the largest economy in the world. As for individual investors, this information becomes essential related to investment decision making that can affect the value of financial assets in the future.

US-China Trade War
America is the country with the largest economy in the world. The World Bank state the value of the American economy in terms of Gross Domestic Product (GDP) reached $ 20.4 trillion in 2018, contributing 23.9 percent of the entire global economy, which is valued at $ 85.8 trillion. America conducts export and import activities to support the domestic economy. America became the largest export country in the world in 2017 with export value reaching $ 778.4 billion, or 14.5 percent of total world exports. In addition, America is also the world's largest importer, representing 10.2 percent of total world imports worth $ 520.4 billion in the same year.
American and Chinese trade relations have been going on for a long time. According to Kashyap and Bothra (2019)  Furthermore, when America began a trade war with China in 2018, the world economy declined from 3.1% to 3%. Malaysia, being the country with the most significant correction in economic growth compared to other countries in ASEAN, fell 1% compared to 2017 of 5.7%. The trade war between America and China does not bring benefit to any country and adversely affects the world economy primarily through increasing prices (Jain and Saraswat, 2019), reducing America's real income by $ 1.4 billion per month (Amiti et al, 2019), and increasing uncertainty which can cause a decrease in investment (Caldara et al, 2019). Also, the trade conflicts of the two most prominent countries in the world caused a decline in the stock price index in the United States and China. More than 3,000 corporate shares in the United States and China have declined and caused the three major indexes in the two countries to experience a correction of more than 3 percent (Zhu et al, 2019). Furthermore, an empirical study conducted by Bown (2019) states that a trade war can trigger a global financial crisis.

ASEAN Stock Market
The capital market is exciting to be the object of research because according to World Bank data, the ASEAN capital market is seen from the value of market capitalization at the level of $ 2.4 trillion in 2018, or grew by 242 percent compared to the value of market capitalization in 2008 at the level of $ 720 billion. This figure is far higher than the growth of the world capital market capitalization in the same period, which is 113 percent. Vietnam's capital market-led with the growth of 973 percent in a decade, while Malaysia became the country with the lowest capital market growth in the ASEAN region, only growing by 110 percent in the last ten years from 2008 to 2018.
The high growth of ASEAN market capitalization was supported by several factors, including Southeast Asia succeeding in developing export activities and attracting foreign direct investment, particularly in inviting multinational companies to invest in ASEAN over the last three decades (OECD, 2019). In other words, this development is inseparable from international trade activities and involves regulations regarding tariffs agreed between countries. Therefore, the trade war caused a decline in exports and imports (Fajgelbaum et al, 2019). Declining export and import activities cause a decrease in trading activity, which can affect company performance. A study conducted by Benguria (2019) explains that thousands of companies from 40 countries with export exposures to China have experienced a decline in revenue, profits, and stock prices since the trade war began.
Literature reviews using event-studies conducted by Arya and Zang (2009) explains that announcements of CSR create positive abnormal returns in South Africa. The market responded positively to CSR announcements, as seen from abnormal stock returns in America (Griffin and Sun, 2012 The research method was conducted using the event-study approach. Event-study is a methodology that can be applied to determine whether abnormal returns occur due to events that were not anticipated beforehand. The assumption in this method is the market is efficient, or stock prices respond quickly to any information. Furthermore, a statistical test (t-test) is used to see whether the American and Chinese trade wars have a significant or insignificant impact on ASEAN capital markets. The t-test calculation is counted by dividing the abnormal return by the standard error of the value of each capital market, provided that if the t-test value is higher than the t-table value of 1.96, with a significance level of 5%, the trade war will have significant impact on the capital market in ASEAN (Caporale et al, 2019).
Event studies can be carried out with three approaches, including (1) determining the time of the event or what is called the "event window", (2) calculating abnormal returns and cumulative abnormal returns in stock prices including pre-event windows and post-event windows, ( 3) measure the level of significance to see whether the event has a significant or significant influence on the object to be measured. The procedure for calculating abnormal returns has been carried out by Xie et al (2019).
The formula calculates stock market actual returns (i) in equation 1.
Where (Pit) is the price of a stock at time t and Pi, t-1 is the stock at a price at time t-1. The expected return (R ît) is calculated by using the Capital Asset Pricing Model (CAPM), the MSCI World Index (Rmt) is used to represent the market index.
Where i is the intercept between stock return and market return, and i is calculated by dividing the covariance of stock return and variance of the market return. The abnormal return (AR) can be calculated as Average abnormal return (AAR) is calculated as Then, cumulative abnormal return (CAR) can be defined as To estimate the CAR of each event in this study, CAR will represent CAR average of the pre-event window, short-term event window and long-term event window.
Now, the hypothesis can be tested by calculating CAR variance as follows Where the ! is defined as standard deviation of a sample of mean abnormal return. T is represented the number of months used for computing CAR, then, t-statistic calculation can be measured as according to several literatures, t-stat can be used to investigate whether the event (US-China trade war) has a significant or insignificant impact on ASEAN stock market cummulative abnormal return for the short-term period.

Findings
The results of descriptive statistical calculations explain the mean stock returns, median values, and standard deviations. The mean score represents the average return on the ASEAN capital market during the period before and during the trade war between the United States and China. The median value depicts the median value of the average return on the ASEAN capital market during the observation period. Whereas the standard deviation reflects the distribution of data from each of the ASEAN capital market returns during the study period.
Descriptive data provides preliminary information to see the relationship between the American and Chinese trade wars on the capital markets of ASEAN countries in the period before the trade war and the impact of trade wars in the short term. The data briefly shows that there was a change in the capital market return in each country during the observation period, namely the capital markets of ASEAN countries before and during the trade war shown in Table 3.  Table 3 explains that the average return on the ASEAN capital market experienced negative performance during the period of the trade war between the United States and China (see Panel C). The return on the ASEAN capital market in the short-term window was -2.61%. The highest weakening was experienced by the Philippine capital market by -4.01%, while the Thai capital market experienced the lowest decline of -1.48%. In contrast, the ASEAN capital market performance experienced growth before the trade war (preevent window) of 3.32%.
The median value of the ASEAN capital market before the trade war was 4.31%. Vietnam became the country with the highest median value compared to other ASEAN countries, 12.75%. On the other hand, the median value of the capital market returns to -2.83% during the American and Chinese trade war. Vietnam's capital market has the highest return decline. The median value of Vietnam's capital market return was 9.94% before the trade war and fell to -3.34% during the trade war between United States and China in March 2018 and June 2018. In addition, the impact of US-China trade war on ASEAN stock market is insignificant.  Table 4 compares the ASEAN capital market returns between the event window and the global capital market (MSCI World Index) and the average return of the American capital market (Dow Jones Composite Index) and the Chinese capital market (Shanghai Stock Exchange). The ASEAN capital market performance is lower than the global capital market. This data can be shown from the ASEAN capital market average return of -0.02% at the pre-event window. The biggest negative return can be seen in the short-event window period, namely March 2018 to June 2018. All ASEAN capital markets have lower returns compared to the MSCI World Index. The Philippines is the country with the highest return difference (-8.04%) compared to the global capital market return. In contrast, the return on the Thailand capital market compared to the global capital market was negative 5.51%. ASEAN capital markets, on average, experienced -6.64% compared to global capital markets. Furthermore, ASEAN stock market return relative to average of US and China stock market returns before US-Chine trade war was 2.95%, it decreased to negative 0.60% during the trade war.
The performance of all ASEAN capital markets experienced negative growth, so it proves that the American and Chinese trade wars had a negative impact on the capital markets in ASEAN countries. The capital market, which is one of the barometers of the country's economy, will relatively reflect economic conditions in the real sector. Furthermore, the financial market tends to respond more quickly than changes in the real sector. In other words, stock prices will move based on investors' perspectives about the future. If the investor perspective is positive, then the stock price will tend to increase, and vice versa. Proxies that are often used to measure index responses to events use Cumulative Abnormal Return (CAR). The period before the trade war (pre-event window) shows that the CAR has higher performance compared to global capital market returns. The average CAR of ASEAN capital markets is 11.96% higher than the global capital market return. Vietnam's capital market leads with a CAR difference of 28.18%, followed by Indonesia and Malaysia of 14.80% and 11.15%, respectively. While the capital market with the smallest return difference compared to the MSCI World Index return is the Philippines, which is 4.88%.
On the other hand, the performance of the ASEAN capital market during the trade war in the short-event window experienced a CAR of -7.37%. All capital markets in ASEAN Overall, the American and Chinese trade wars had a negative impact on the ASEAN capital market. The ASEAN capital market return on average experienced positive returns before the trade war, and the performance turned negative when the trade war occurred. This figure also explains that the trade war has an impact on the capital markets of ASEAN countries, which is reflected in the average return on capital markets in ASEAN. While the t-test value is -0.329 or smaller than 1.96%, this explains that the relationship between the American trade war and China have insignificant impact on the capital markets in ASEAN countries. This study has limitations on ASEAN stock market. For further research, we can estimate the global stock market during US-China trade war and other economics or financial events.

Conclusion
This study aims to find the impact of the trade war between America and China on the performance of ASEAN countries' capital markets with an event-study approach. We use monthly clsong stock price of each ASEAN stock market over the period from January 2009 to June 2018. The data were collected from the yahoo.finance and investing.com websites. This research investigates three periods to find the impact of US-China trade war, namely estimation window or nomal period ( The results of this study explain that the trade war has a negative impact on capital market performance in six ASEAN countries, namely Indonesia, Malaysia, Singapore, Thailand, Philippines, and Vietnam. In addition, the performance of the ASEAN capital market based on CAR is also lower than the MSCI World Index during the American and Chinese trade war period, although the impact of the trade war is not significant on the ASEAN capital market. Finally, the results of this study illustrate that several economic events that occurred in developed countries can have a spill-over effect on ASEAN capital markets. Not only the American and Chinese trade war, but the British policy to exit the European Union (Brexit) also has a negative impact on the economy in ASEAN (Estrada et al, 2019).