100 /304
媒體聲譽對企業社會責任得獎企業其股市表現與財務績效之影響
100
where
AveMEDIAP
is the average media exposure of firm
i
during the period from
T
m
days prior to the CSR announcement date to the announcement date (
T
0
).
AveMEDIAA
is
the average media exposure of firm
i
during the period from the CSR announcement date
(
T
0
) to
T
m
days after the announcement date, with
m
ranging from 0 to 150 trading days.
3.4 Sentiment Ratio Measure Using Semantic Orientation
The concept of ‘semantic orientation’, as proposed by Hatzivassiloglou and
McKeown (1997), indicates that an article not only transmits objective facts, but also
expresses subjective sentiment and opinion; however, there is no representative system
capable of revealing or constructing information sentiment for Chinese documents. We
therefore collect Chinese financial news reports and carry out a process of information
quantification, as illustrated in Figure 2, by referring to Lu and Wei (2014) and Lu, Chen,
Ker, and Wei (2015).
Training
Sample
Testing
Sample
The process from
quality to quantity
Selection of daily financial news
reports during the sample period
Noise Filtration using part-of-speech
tagging and chi-square test
Selection of characteristic terms for
optimism and pessimism in Chinese
Construction of Chinese
financial news indicator
Word segmentation using the
Chinese word segmentation system
http://ckipsvr.iis.sinica.edu.tw/Calculation of term frequencies
of the characteristic terms for
optimism and pessimism
Figure 2 Information Quantification Process
Source: The information quantification process illustrated in this figure was obtained from Lu and
Wei (2014) and Lu et al. (2015).