Fuzzy Mediation Analysis for KOSPI-Related Variables

Abstract

Stock prices and bond interest rates are inversely related. The current account plays the most important role in the rise of composite stock index. When the trade surplus increases, stock prices rise sharply. Conversely, when the exchange rate and government bond interest rates increase, the composite stock index decreases. The stock index is influenced by several economic variables, politics, the economy, and investment sentiment. In real situations, such financial variables are mostly fuzzy variables. For example, the Korea Composite Stock Price Index (KOSPI) is recorded based on the closing price. However, the daily KOSPI has many values, such as the open price, low price, and high price; therefore, if only the closing price is used for analysis, only partial information is. To analyze the relationship between KOSPIrelated variables, the KOSPI, stock deposits, government bond interest rates, and foreign security investment data are applied. We investigated the mediated relation of variables, known as mediation analysis. In particular, we implemented fuzzy mediation analysis owing to the ambiguity of given data. In the data analysis, we proposed several fuzzy mediation models using fuzzy transformed data.

Convexity-Cum-Concavity on Fuzzy Soft Expert Set with Certain Properties

“…Since its appearance, several researchers have presented different methods and algorithms for solving decision-making problems in a soft environment. For example, Feng and Zhou [8] presented a soft discernibility matrix, Cagman and Enginoglu [9] presented the concept of a soft matrix, Hasan et al [10] discussed a fuzzy model for reducing the risk of insolvent loans in the credit sector as applied in Egypt, and Kim et al [11] investigated a fuzzy mediation analysis for KOSPI-related variables.…”