雙頭壟斷情境下電信營運商之費率研究 —以行動上網為例

Abstract

本研究探討一個雙寡頭壟斷的市場，先進者和後進者皆為行動網路服務業者。假設先進者的資費方案已經公佈，而後進者的則是尚未公佈。後進者的目標是設計一個資費方案，以最大限度地提高其利潤，同時後進者的比例比對到先進者的約束下應不低於以保持市場均衡的比例(ρmax)更高。先進者公佈K個方案在市場上, 每個方案的內容可由 (r ̃i,h ̃i,m ̃i) 表示。當消費者選擇第i個方案時，每個月必須支付r ̃i在不超過限額用量h ̃i (GB)的情況下，,且當用量超過限額用量h ̃i (GB)時，每GB需額外支付m ̃i。而最後一個方案(第K方案)內容可由(r ̃K, h ̃K=∞, m ̃K=0 )表示，消費者不論使用多少GB每個月都只需支付月租費r ̃_K。後進者採用相似的方案內容(ri, hi, mi)穿插在先進者方案之間和(rB, hB =∞, mB =0)。 本研究發展一個模型得最佳的後進者方案內容(ri, hi, mi)達到後進者營收最大的同時維持市場均衡。 研究中，我們假設消費者的預算與需求分配可由市場調查取得。

This research investigates a duopoly market which involves a leader and a follower both operating mobile internet services. Assume that the tariff scheme of the leader has been announced to the market and that of the follower is not announced yet. The follower aims to design a tariff scheme to maximize its profit, under the constraint that the follower’s proportion compared against to that of the leader should not be higher than a ratio (ρmax) in order to keep the market in equilibrium. The announced tariff scheme of the leader has K alternatives, each of which can be represented by (r ̃i,h ̃i,m ̃i) which denotes that a customer adopting alternative i has to pay r ̃i dollars each month if his monthly usage is no more than h ̃i GB, and has to additionally pay m ̃i dollar per extra GB when his monthly usage exceeds h ̃i GB. The last one (Kth alternative) can be represented by (r ̃K, h ̃K=∞, m ̃K=0 ) which denotes that a customer can use as much GHZ as he wish once he has committed to pay r ̃K dollars each month. The follower adopts a similar tariff scheme (ri, hi, mi), 1≤i≤B and (rB, hB =∞, mB =0). This research develop a model to optimally determine B and (ri, hi, mi), 1≤i≤B in order to maximize the follower’s profit while keeping the market in equilibrium. In the study, we assume that the probability distribution of customers’ budgets and demand quantity in terms of internet services could be obtained by market surveys.