本研究主要是以「電信三雄」-中華電信、台灣大哥大及遠傳電信為研究對象,採用月資料,研究期間為2001年1月至2011年12月,探討總體經濟變數如何影響電信業者之營收。利用時間序列方法,進行態動分析,以向量自我迴歸模型 (VAR) 之衝擊反應函數及 Granger 因果關係檢定等方法,實證研究總體經濟變數對電信業經營績效的影響。本實證研究結論歸納如下: 1.運用Granger 因果關係檢定,總體經濟變數變動時對電信三雄營收變動確實存在因果關係。通訊業人口變動率顯著影響中華電信營收變動率及台灣大哥大營收變動率;消費者物價指數變動率顯著影響中華電信營收變動率;失業率變數顯著影響遠傳電信營收變動率。 2.利用 VAR 模型發展出衝擊反應函數,在短期方面,物價指數變動率、失業率變動率、通訊業就業人口變動率變動,會影響中華電信、台灣大哥大及遠傳電信營收變動;長期累積效果大致呈現收斂現象。 3.利用 VAR 模型之預測誤差變異數分解得知,中華電信、台灣大哥大及遠傳之營收變動率、自身解釋的程度相當高 (皆大於60%),均不易由外在因素來加以解釋,顯示三家電信公司營收變動率之內生性很強。
This research is to explore how macroeconomic variables affect carriers’ revenue with special focus on the three "Telecommunications" Giants - Chunghwa Telecom, Taiwan Mobile and Far EasTone, using monthly data from January 2001 to December 2011. Dynamic analysis is conducted to study the effects of macroeconomic variables on the operating performance of the telecommunications industry using time series approach and the impulse response functions of vector autoregressive model (VAR) and Granger causality test. The empirical findings are summarized as follows: 1. Using Granger causality test, we have found out that changes in macroeconomic variables have a casual relationship with the revenue changes of the three Telecommunications Giants. The change rate of the telecommunication industry population has a significant impact on the change rate of Chunghwa Telecom revenue as well as Taiwan Mobile revenue. The change rate of the consumer price index can significantly affect the change rate of Chunghwa Telecom revenue. In addition, the unemployment variables can also have influence on the change rate of EasTone Telecommunication revenue. 2. Using the impulse response function of VAR model, we also find out that , in the short term, the change rate of the consumer price index, unemployment, and the communications industry population, can affect the change rate of the revenue of Chunghwa Telecom, Taiwan Mobile and Far EasTone. Long-term wise, the cumulative results show the convergence. 3. Using the variance decomposition forecast errors of the VAR model variance we also find out that the change rate of the revenue of Chunghwa Telecom, Taiwan Mobile and Far EasTone can be explained by internal factors (all greater than 60%), not by external factors. This reveals that the revenue’s change rate of the three Telecommunications Giants is something intrinsically.