Market Impact Analysis of Financial Literacy among A-Share Market Investors: An Agent-Based Model Rongtian Zhou; Xiong Xiong; Bàrbara Llacay; Gilbert Peffer Entropy · 2023-11-29 CC BY 4.0 · https://creativecommons.org/licenses/by/4.0/ Source: https://pmc.ncbi.nlm.nih.gov/articles/PMC10742982/ Abstract Financial literacy has become increasingly crucial in today’s complex financial markets. This paper explores the impact of financial literacy on the stock market by establishing an artificial financial market that aligns with the characteristics of the Chinese A-share market using agent-based modeling. The study incorporates financial literacy into investors’ mixed beliefs and simulates their behavior in the market. The results show that improving individual investors’ financial literacy can improve market quality and investor performance, as well as reduce the unequal distribution of wealth to some extent. However, the phenomenon of speculative trading and irrational behavior in the market can pose potential risks that require regulatory measures. Thus, policy recommendations to improve individual investors’ financial literacy and establish corresponding regulatory measures are proposed. Keywords: financial literacy, investor behaviour, agent-based model, A-share market 1. Introduction With the development and complexity of financial markets, the importance of financial literacy is increasingly recognized. Financial literacy refers to an individual’s comprehensive understanding and application ability of financial knowledge, skills, and attitudes, including both personal financial management and the ability to use financial products and make investment decisions. An individual with high-level financial literacy can not only better manage their finances and investments, but also better adapt to, and respond to, changes and risks in financial markets [1]. Compared with the capital markets in developed countries, China’s capital market is relatively new, especially in the development of the stock market. In terms of financial literacy, there is a significant disparity between urban and rural areas in China, particularly in more remote rural areas. Simultaneously, Chinese investors may exhibit some unique investment habits, such as a greater inclination toward participating in the stock market and demonstrating relatively higher trading activity in stocks [2]. At the policy level, in recent years, the Chinese government has also started to address the issue of investor financial literacy and has repeatedly put forth policies related to investor financial education [3]. Existing research is trying to fully understand the complex relationship between financial literacy and the stock market. According to Gallego-Losada et al. (2022) [4], higher financial literacy is associated with a greater likelihood of engaging in financial information search and processing, and, thus, results in better performance. However, there has been a lack of research that can quantitatively and precisely measure the impact of financial literacy on investor behavior and the market in the stock market, especially for the Chinese A-share market where retail stock participation is higher. In-depth research on the impact of Chinese investors’ financial literacy on the A-share market becomes particularly meaningful. Therefore, in this paper, we integrate financial literacy with investor behavior by incorporating financial literacy into investors’ mixed beliefs and reflecting it in their ability to process financial news or events. A model based on agent-based modeling is established to measure the role of financial literacy in the stock market. This paper aims to explore the role of financial literacy in the stock market through the agent-based modeling method and provide specific recommendations and plans. The main innovations of this study can be summarized in three aspects. Firstly, our study circumvents the complexity of measuring financial literacy and the potential for omitted variables, which is common in traditional empirical analysis methods. Instead, we innovatively approach the issue by focusing on the outcomes of financial literacy, successfully investigating how changes in financial literacy affect the market. Secondly, our study intricately classifies investors by capital scale during the measurement of financial literacy and provides policy recommendations for enhancing financial literacy tailored to specific investor categories. Lastly, our study fills a literature gap in the application of agent-based modeling to the topic of financial literacy. To be precise, we will first incorporate financial literacy into investors’ mixed beliefs, i.e., incorporate each investor’s financial literacy to reflect the proportions of their investment behavior attributable to fundamentalist, chartist and noise-induced components. Rather than delving into the intricate “black box” process of how financial literacy influences decision-making from the inception of investor financial literacy to decision provision, our model directly assesses the outcomes of financial literacy as the ability to make faster decisions and predict the future direction of stocks with greater accuracy. After that, we simulate the behavior of investors with different levels of financial literacy in the stock market and compare their investment performance and the resulting market impact. Using the agent-based modeling method, we will more accurately quantify the performance and market impact of investors with different levels of financial literacy and identify the factors that affect these performances and impacts. We will also determine what happens if the financial literacy of all investors or a particular group of investors is enhanced through certain measures. We hope that this research can contribute to improving the financial literacy of individuals and society, as well as promoting the stability and sustainable development of the financial market. 2.1. Financial Literacy In recent years, financial literacy has become a popular research topic. Many scholars have extensively explored the concept, meaning, measurement methods, and influencing factors of financial literacy. In the stock market, many studies have also investigated the impact of financial literacy on investor behavior, market volatility, and the development of the stock market. Several studies have examined the relationship between financial literacy and stock market participation. For example, in a study by Lusardi (2019) [5], individuals with higher levels of financial literacy were found to be more likely to participate in the stock market. This study also indicates that individuals with high financial literacy have greater opportunities to access information and can process information more efficiently. Cossa et al. (2022) [6] investigated the impact of financial literacy on individual financial well-being. They found that individuals with higher levels of financial literacy were more likely to hold stocks in their investment portfolio. Other studies have focused on the impact of financial literacy on stock market performance. Deuflhard et al. (2019) [7] examined the relationship between financial literacy and savings account returns. The authors found that individuals with higher levels of financial literacy tended to have higher savings account returns. Baker et al. (2019) [8] explored the relationship between financial literacy, demographic variables, and behavioral biases. The authors provided evidence to suggest that financial literacy can help individuals make better financial decisions. In addition, several studies have examined the impact of financial literacy education on stock market outcomes. Compen et al. (2019) [9] examined the impact of financial literacy education on subsequent financial behavior and found that financial literacy education had a positive impact on stock market participation and investment behavior. Pettersson (2022) [10] found that financial literacy education had a positive impact on investment knowledge and behavior in the stock market. However, not all studies have found a positive relationship between financial literacy and stock market outcomes. Al-Bahrani et al. (2019) [11] found that financial literacy was not associated with stock market participation or investment behavior. Bottazzi and Lusardi (2021) [12] explored the relationship between financial literacy and savings behavior using data from the Programme for International Student Assessment (PISA). The result showed that financial literacy was not associated with stock market performance. Furthermore, several studies have highlighted the importance of financial literacy in mitigating risk in the stock market. For instance, a study by Humaidi et al. (2020) [13] found that financial literacy was positively associated with risk management behavior in the stock market. Similarly, a study by Yang et al. (2018) [14] found that financial literacy was positively associated with the use of risk management strategies in the Chinese A-share market. Liao et al. (2017) [15] found that in terms of financial literacy’s impact on investor market participation and risk management, investors in the Chinese A-share market did not differ significantly from investors in other developed countries around the world. In conclusion, previous research suggests that higher levels of financial literacy are associated with greater stock market participation, better investment behavior, higher stock market returns and better risk management. Financial literacy education may also have a positive impact on stock market outcomes. Despite existing research attempts to understand the intricate relationship between financial literacy and the stock market, empirical studies often face challenges in capturing certain psychological or social factors due to the inherent complexity of financial literacy. Therefore, adopting an agent-based approach that is outcome-oriented from the perspective of financial literacy can yield more comprehensive evidence and conclusions, which is an area largely unexplored in the current literature. 2.2. Agent-Based Modeling Agent-based modeling is a scientific research method based on computer models that simulate the behavior and interactions of autonomous agents in a complex system [16]. Agent-based models represent the system as a collection of individual agents, each with its own unique characteristics, rules, and behaviors. These agents interact with one another and with their environment, often resulting in emergent patterns and behaviors that can be difficult to predict using traditional mathematical models. Agent-based models can test and compare multiple variables in simulated financial markets, thereby more accurately predicting and evaluating changes and risks in financial markets. However, agent-based modeling may also have some limitations such as data requirements and validation challenges, as accurate agent-based modeling often demands detailed data on individual agents and their interactions, which may not always be readily available or feasible to collect, and researchers should ensure that the model’s behavior aligns with real-world observations and is a faithful representation of the system under study, which may be difficult. The agent-based modeling method has been widely used to evaluate the effectiveness of investment portfolios, predict market volatility, and other aspects. Yang et al. (2022) [17] discussed the use of the method in studying market microstructure, financial crises, and market regulation. Dehkordi et al. (2023) [18] provided a comprehensive overview of the use of agent-based modeling in finance, including its strengths and weaknesses. They argued that the method can provide valuable insights into market behavior, but that care must be taken in constructing the models to ensure they accurately reflect the real-world dynamics of financial markets. Axtell and Farmer (2020) [19] reviewed the use of the method in studying market stability, asset pricing, and other aspects of finance. They argued that agent-based modeling has the potential to transform our understanding of financial markets and improve our ability to predict and prevent financial crises. In empirical study, the influence of financial literacy on stock market participation and financial behavior is well established. However, in this work, the agent-based modeling method has unique advantages. First, it can consider investors with different levels of financial literacy in the experimental environment, avoiding interference factors that are difficult to control in the actual market. However, in empirical research, there is a possibility of omitted variables or a lack of certain unobservable changes in investor sentiment or psychological aspects [20]. Second, the agent-based modeling method can quickly generate a large amount of data, thereby improving the accuracy and credibility of the research [21]. Finally, through the analysis of the experimental results, we can determine what will happen if we implement certain measures to enhance the financial literacy of all investors or a particular group of investors, such as strengthening information disclosure or providing more investor education. These measures require significant costs to implement. In particular, investor education is a long-term and resource-intensive undertaking, and its effectiveness is uncertain. Empirical research can only analyze outcomes that have already occurred, while agent-based models have a forward-looking nature, which can reduce the trial-and-error costs of policies. Therefore, through agent-based modeling, we can simulate their effects and provide evidence-based policy recommendations. 3.1. Market Design In this section, we describe an artificial stock market designed to emulate the characteristics of the Chinese A-share market. The synthetic market comprised four segments: Shanghai main-board (SHM Market), Shenzhen main-board (SZM Market), Second-board (SB Market), and Sci-Tech Innovation board (STAR Market). Real A-share market data were employed to fine-tune the features of stock prices, equity, and volatility within these four sectors (refer to Appendix A for calibration results). To align with the real market’s attributes, we created a simplified limit order book market model that adhered to specific traits of the Chinese stock market, including: 3.2. Trader Types and Structure There were 5000 traders in the model. To examine the impact of financial literacy changes on different traders, we classified all individual accounts into five categories based on account-level transaction data: (1) Retail: less than RMB 100,000; (2) Sinvestor: between RMB 100,000 and 500,000; (3) Minvestor: between RMB 500,000 and 5 million; (4) Linvestor: between RMB 5 million and 10 million; and (5) XLinvestor: larger than RMB 10 million. We also included institution accounts as a separate group, which included mutual funds, insurance companies, security firms, and pension funds (the investor structure data of Shanghai main-board (SHM Market) and Technology Innovation Board (STAR Market) were drawn from the 2019 Shanghai Stock Exchange Statistics. The investor structure data of Shenzhen main-board (SZM Market) and Second-board (SB Market) were derived from the 2019 Investor Structure and Behavior Analysis Report of Shenzhen Stock Exchange). The specific number and wealth distribution of the five categories of investors can be found in Section 4.1, where the parameters of the model are set. Next, we defined the portfolio wealth for each agent. Upon entering the market initially, traders received an allocation of both stock and cash. The initial stock position S0i,j for agent i was: where SMeanj was the position of each trader equally allocated to stock j, and φ followed a uniform distribution between 0.01 and 0.99. The assumed initial cash position α0i for agent i was: where p0j was the initial price of stock j. The optimal composition of the agent’s portfolio was determined in the usual way by trading-off expected return against expected risk. However, the agents were not allowed to engage in short selling. Specifically, when the total wealth of a trader was negative, we considered the trader to be bankrupt. At this time, a new trader would enter the market to ensure the normal operation of the agent-based model (Based on simulation data, during normal market operations, the percentage of such traders was minimal, and the augmented wealth of investors had an insignificant impact on the market. In the event of a market crash, the proportion of new traders would expand. However, the primary market driver did not lie in augmenting traders' wealth, thereby resulting in a negligible impact on the model.) 3.3. Traders Financial Literacy and Price Expectations Financial literacy is a complex factor encompassing the information processing ability mentioned, along with various other socioeconomic or psychological abilities. It is challenging to articulate this comprehensively in both empirical and experimental research. Fortunately, in an agent-based model, we can measure an individual’s level of financial literacy by their precise control over the outcome of a particular event. For instance, in the case of negative news, investors with high financial literacy are more likely to quickly acquire information, synthesize various factors such as market sentiment, socioeconomic conditions, and personal considerations, and efficiently draw conclusions about the decline in stock prices. They can also make more accurate predictions about the extent of the decline. On the other hand, investors with low financial literacy may acquire information more slowly and arrive at conclusions with greater deviations. The process from the appearance of information to drawing conclusions involves a series of “black box” operations, including information acquisition and internal cognitive processes, which are not observable. However, in an agent-based model, we can infer from the results: investors with high financial literacy will exhibit differences in the speed and accuracy of their reactions to market information, compared with those with low financial literacy. In accordance with Chiarella et al. (2017) [22], the demand for the risky asset by each trader was assumed to comprise three components: a fundamentalist component, a chartist component, and a noise-induced component. However, rather than simply using statistical data as parameters, we incorporated each investor’s financial literacy to reflect the proportions of their investment behavior attributable to fundamentalist, chartist and noise-induced components. Furthermore, the fundamental value of stocks in the market was not transparent or fixed, but rather varied among individuals and changed with time and various events. The level of financial literacy reflects investors’ abilities to obtain information and process events, thereby affecting their estimation of the fundamental value of stocks and their sensitivity to changes in fundamental value. At any time, t, a trader was chosen to enter the market. The chosen agent, i, formed an expectation about the stock return, rt+τi,j, where τi represents the agent’s time horizon. Agents utilized a blend of fundamental value and chartist rules to shape expectations regarding stock returns, resulting in: where the quantities xi and yi represent the weights given to the chartist and fundamentalist components, respectively. For normalization purposes, we assumed that xi+yi+zi = 1. We assumed that xi=βeLi and zi=(1−β)1−Li, where Li is the financial literacy of agent i, and β represents the conversion strength of investor financial literacy. Barber and Odean (2000) [23] indicated that investors with a high level of financial literacy are more inclined to make investment decisions by thoroughly analyzing fundamental factors such as a company’s financial statements and industry prospects. They are also more likely to opt for long-term stock holdings rather than frequent trading. The study also indicated that 20% of trades are noise trading and are hazardous. Therefore, the β was set as 80% in our model. Equation (3) also means that if an investor is completely lacking in financial literacy, i.e., Li=0 (which will not happen in most cases), they will be completely unable to access useful financial news or events, or obtain price information from such news or events. Therefore, they would have no choice but to be a pure momentum-based trader, relying solely on the historical price trend to make their stock price predictions with a maximum proportion of noise-induced component of 0.2. In another extreme case, i.e., when Li=1, the investor would have full information of the market and would be able to immediately perceive the fundamental changes in the value of a stock and accurately determine its value. In this case, the trader would still have speculative motives (xi>0), which means they would also engage in momentum trading and profit from price fluctuations. xi=βeLi also indicates that the higher the financial literacy of agent i, Li, the smaller the proportion of chartist components the agent will have, while there is a diminishing marginal benefit to improving financial literacy. The variable ε, featuring a zero mean and variance σε to agent’s expectations, signifies the noisy beliefs of investors. rci,j indicates the anticipated future trend of the chartist component derived from observations of spot returns over the last τi time steps. In other words, where p¯τi/4j is the short-term average price of stock j, and p¯τij is the long-term average price of stock j. rfi,j represents the trader’s predicted return on stock j based on fundamental beliefs, that is, where ptj is the price of stock j at time t. The variable τi represents the time scale over which the fundamentalist component calculates the mean reversion of the price to the fundamental. f^ti,j is the fundamental value of stock j predicted by agent i, that is, where ftj is the real fundamental value of stock j at time t. Equation (6) means that the higher the financial literacy, the less the agents will be influenced by historical price trends, and their predictions will be closer to the real fundamental value of stocks. It is common to assume that the time horizon of an agent depends on its characteristics. Fundamentalist strategies are typically given much greater weight by long term institutional investors who have longer time horizons, whilst day traders have shorter time horizons and give more weight to chartist rules. Hence, we chose the time horizon τi of each agent according to: We assumed that each trader arrived to the market according to a Poisson process with parameter λi=ω/τi and traded continuously. The future price, pf,ti,j , expected at time t by agent i was given by: 3.4. Order Submission Rules Traders trade only when their expected order profit from trading is high enough to offset the transaction cost. In a dynamic equilibrium model of an order driven market with asymmetric information, Foucault et al. (2016) [24] showed that informed traders submit both market orders and limit orders, depending on whether their information advantage is above or below a cutoff value. Gil-Bazo and Ruiz-Verdú (2009) [25] introduced similar order submission rules, being that traders submit market orders when the price deviations from their forecasting fundamental value are large, and limit orders when the deviations are small. Depending on traders’ forecasting and order book states, traders submit either limit or market orders. We introduced similar order submission rules. When trader i arrived in the market at time t, within the time period t, they assessed their expected price pf,ti,j against the current best bid btj and best ask atj factoring in the transaction cost u=1%ptm,j, where ptm,j was the midpoint of the optimal bid and ask quotes. Depending on the current order book, following Sornette and Zhou (2006) [26], we considered four scenarios that aligned with the characteristics of the order book in the Chinese A-share market, summarized in Table 1. In the first scenario, where there was at least one ask and one bid in the current limit order book, the trader placed a market order to buy if their expected price pf,ti,j was above the sum of the best ask atj and the transaction cost u, i.e., pf,ti,j−u>atj. Conversely, if their expected price pf,ti,j was below the best bid btj minus the transaction cost u, i.e., pf,ti,j+u