News analysis provides Theme Frequency in News Indices (TFNI) that address information about 15 important fields in economy. The TFIs are computed based on about 4,000 economic news articles every day that are scraped from the internet. The total number of news articles used for this analysis is about 18 million.

$$TFNI_{t}=\sum\limits_{i=1}^{N_t} \hat{A}_i^{(t)} / N_t,\qquad \hat{A}_i^{(t)} = \bigvee\limits_{m=1}^{M_i} C_{im}^{(t)},\qquad C_{im}^{(t)} = \prod\limits_{k=1}^{K}\bigvee\limits_{l=1}^{L_k} I_{S_{im}^{(t)}}(w_l^{[k]})$$

where \(\Omega_t=\{A_1^{(t)},\cdots,A_{N_t}^{(t)}\}\) is the set of news articles at time \(t\), and the indicator identifies whether a sentence contains the word groups defining a specific economic field.

Market analysis compares the Text-based Business Confidence Indicators (TBCI) to the corresponding KOSPI indices by field. TBCIs are computed based on about 2,000 analyst reports per month generated from about 50 investment banks in Korea. The total number of analyst reports used for this analysis is about 130 thousand.

$$TBCI_{i,t}=\frac{X_{i,t}-\bar{X}_{i,.}}{s_{i,.}}\times 10+100$$

where \(X_{i,t}\) summarizes the balance of positive and negative sentences for field \(i\) at time \(t\).

Factor analysis provides the Text-based Business Condition Factors (BC-factors) that show the top 5 issues in 40 industries that affect their business condition. BC-factors are computed based on about 2,000 analyst reports per month generated from about 50 investment banks in Korea.

$$BC\text{-}factors_{i,t}^{5}=\{(w^{[K]},\cdots,w^{[K-4]})\mid w^{[k]}=f(v_{(k)}),\;v=m_{U_{i,t}\setminus W}(w)\}$$

N: the number of sentences analyzed / C: the number of companies analyzed / A: the number of IBs that wrote the reports for the corresponding company, field, and time.

Event analysis provides examples of Text-based Impact of an Event Indicators (TIEI) and Text-based Evaluation of an Event Indicators (TEEI) for events selected for their importance in the economy.

$$TIEI^{\mathcal{A}_w}_{i,t}=\frac{\sum_{s\in S_{i,t}} I(s\in\mathcal{A}_w)}{|S_{i,t}|}\times100,\qquad TEEI^A_{i,t}=\frac{X_{i,t}-\bar{X}_{i,.}}{s_{i,.}}\times10+100$$