Did the Inclusion of China’s A-Shares in the MSCI Index Improve the Information Content of Listed Firms? Analysis Based on Stock Price Synchronisation and Environmental Social Governance

Table 1

Relevant theories.

Theory	Topic	Literature
Information asymmetry theory	Those with adequate information are typically in a favourable position, whereas those lacking information are in a relatively disadvantageous position.	[3–6]
Signal transmission theory	Active transmission can effectively improve the information transmission efficiency between information-advantaged party and the poorly informed party in the transaction and reduce the degree of information asymmetry.	[7, 8]
Financial risk contagion theory	The risks that a country will face are domestic and global risks, and the risk contagion effect will increase financial risks.	[10, 11]
Information efficiency theory	Stock price synchronisation reflects the ability of a firm to absorb information that is unique to the enterprise. Stock price synchronisation is an essential indicator of the information efficiency of the capital market, which means that the vast majority of stock prices will show the same upward or downward trend over time.	[13–16]