Peni Rahmadani, Adler Haymans Manurung
Jurnal Indonesia Sosial Teknologi, Vol. 5, No. 11, November 2024 4816
Estimating volatility and analysing its relationship to equity risk premiums has
become the focus of research in the financial sector. The Capital Asset Pricing Model
(CAPM), as expressed by Sharpe (1964), Lintner (1965), and Black (1976), highlights
the positive relationship between risk or volatility and the expected return of a security.
Manurung's (1997) research found a positive relationship between market volatility and
market risk premiums, although the difference was insignificant from zero.
Research on volatility has been widely conducted by previous researchers, such
as Banumathy & Azhagaiah (2015), who examined the stock market in India; Lin (2018),
who examined stock volatility in China using the GARCH model; Nghi & Kieu (2021)
who analysed stocks in Japan and Vietnam, and Yahaya et al. (2023) who investigated
stock volatility in Nigeria (NGX). Meanwhile, research on risk premiums has been
conducted by Morawakage et al. (2019) and Yue et al. (2023)
However, research specifically addressing risk premiums in emerging markets
remains limited. The current study fills this gap by examining the relationship between
market equity premiums and volatility in Indonesia, particularly during the pandemic
period. This focus provides valuable insights into how emerging markets respond to
global crises and informs investment strategies in similar contexts.
Moreover, the urgency to understand the role of risk premiums in Indonesia is
underscored by the need to stabilize financial markets amidst heightened uncertainty.
Risk premiums offer a lens through which investors can evaluate the trade-offs between
potential returns and associated risks. The insights from this study aim to contribute to
more resilient market strategies, enabling stakeholders to navigate both current and future
economic challenges effectively.
In this article, we employ the GARCH (1,1) model to analyze the relationship
between market risk premiums and volatility in the Indonesia Stock Exchange (IDX). By
doing so, the study seeks to provide a comprehensive understanding of how these
variables interact under normal and crisis conditions, with implications for broader
economic resilience and investor confidence.
Methods
This research uses daily closing price data from the Jakarta Composite Stock Price
Index (JCI) listed on the Indonesia Stock Exchange. The index is weighted and includes
all stocks listed on the IDX, with the daily closing price used to calculate the composite
index. The data sample used in this study includes JCI with daily time series data from
January 1, 2010, to December 31, 2023. Stock trading on the regular market is done five
working days a week. Data is collected by downloading daily composite stock price index
price index information from the Yahoo Finance website.
Data
Composite Stock Price Index (JCI)
The Jakarta Composite Stock Price Index (JCI) is an indicator that describes the
movement of stock prices (Gumanti, 2011). The index also functions as an indicator of
market trends, meaning that the movement of the index describes the condition of the
market at a particular time, whether the market is active or sluggish (Mukmin, 2015). JCI
can be calculated by the following formula (Tobing and Manurung 2008)