How does Thai stock market react to the environmental policy announcements?

Abstract

This paper investigated the impact of environmental policy announcements to the stocks in the Stock Exchange of Thailand. The announcements are related to climate change in the world forum (Paris Agreement) and plastic waste management. Investors are aware of the environmental policy which could have an impact to firms. We found that 7 out of 8 announcements experienced significant cumulative abnormal returns (both positive and negative). In terms of industry, the only industry which reacted to all announcements is industrials. The majority of firms in the industrials industry are operators related to chemicals, automotive and general manufacturing which are more likely to be sensitive to the environmental issues than other industries.

We further investigated the impact of firms’ environmental disclosure on the cumulative abnormal return. We proxied ESG disclosure and ESG score as one of the indicators for degree of environmental-friendly. The empirical results showed that ESG disclosure had negative impact on cumulative abnormal return at the first action of Thailand towards climate change (signing Paris Agreement) in 2016 (announcement no.2). In contrast, the ESG disclosure had positive impact on cumulative abnormal return to the announcement of Thailand’s commitment to lower temperature rising in the COP meeting in 2021 (announcement no.8). This implies that the investors viewed the impact of ESG disclosure on firms differently before and after the ESG become active in Thailand. In other word, the investors recently view that firms with ESG disclosure are likely to be better at the adaptation to new environmental policies. Additionally, among the firms with ESG disclosure, the ESG score doesn’t have impact on cumulative abnormal return.