1. INTRODUCTION
One of the most controversial issues in today’s investment world is the challenge
posed to the value of fundamental analysis as a reliable tool to reach profitable investment
decisions. Despite it being supported by numerous academic research as a useful means of
stock trading, the fundamental analysis has raised many questions relating to the efficient
market hypothesis (EMH). According to EMH, one cannot exploit both the historical and
publicly available information to gain profits if a stock market is semi-strong form efficient.
Specifically, if the stock market is efficient, no profitable trading strategy can be formed
based on published financial statements. However, the fact that (1) numerous academic
researchers find that the fundamental analysis is a useful tool to predict future earnings and
stock returns; and (2) financial ratios have long been employed by investors and financial
analysts for fundamental analysis, have raised a question relating to the usefulness of
accounting information to predict future stock returns. This question may have been
extensively addressed in developed countries, but little has been done on emerging markets,
and even if there have recently been some findings, the results are neither solid nor reliable
due to the limited numbers of samples. Therefore, this paper aims at examining whether
historical accounting information can be used to predict future stock returns for Thai stock
markets.
Lev and Thiagarajan (1993) document that financial signals have predictive power in
explaining contemporaneous stock returns of U.S. firms and Abarbanell and Bushee (1998)
show that forming investment portfolios by longing high-score stocks and shorting low-score
stocks based on fundamental signals suggested by Lev and Thiagarajan (1993) yields
significant positive returns. In addition, empirical results in Piotroski (2000) and Mohanram
(2005) suggest that a portfolio with higher composite scores earn higher future returns for
high and low book-to-market (BM) firms in U.S. markets, respectively. The composite score
in Piotroski (2000) is constructed based traditional financial measures in three aspects:
profitability, leverage and liquidity, and operating efficiency while the composite score in
Mohanram (2005) is constructed based on traditional profitability measures as well as
growth-oriented measures.
In Japan, Nguyen (2003) constructs a simple financial score for each sample firm and
finds that the financial scores exhibit a strong correlation with contemporaneous and future
market-adjusted returns. In Thailand, Sukanjanapong (2007) documents that historical
financial ratios can be used to form profitable stock portfolios, particularly in the small low
BM stocks.
This paper empirically examines whether investor-friendly composite scores
constructed based on historical accounting information can help investors earn excess future
returns for listed firms in the Stock Exchange of Thailand (SET) and the Market for
Alternative Investment (mai) during 1994 to 2008. Consistent with Piotroski (2000) and
Mohanram (2005), this paper employs simple, yet comprehensive sets of financial measures
to construct two composite scores -- “Value Stock” score (VSCORE) and “Growth Stock”
score (GSCORE). The composite scores are the sum of binary scores (1 or 0) marked from
each individual financial measures. VSCORE represents nine financial measures suggested
by Piotroski (2000). These financial measures include signals related to profitability,
leverage/liquidity, and operating efficiency. GSCORE represents seven financial measures
suggested by Mohanram (2005). These measures include signals related to earnings stability,