台灣DRAM廠商營運績效之關聯性

Abstract

本文是使用時間序列的方法分析DRAM產業垂直分工廠商營運績效的關聯性，探討上中下游廠商的關係是競爭關係─為非輸則贏的利潤分配關係；或是競合關係─為雙贏的利益共享關係。研究發現DRAM上中下游產業，長期間不具有穩定均衡關係。在稅前純益及營業利益項目，上中下游產業在短期內只受其本身的影響，但營業收入及營業毛利項目，設計業及封測業短期內除了只受其本身的影響，亦會相互受到影響。因果檢定得知，上中下游產業間除了在稅前純益項目外，在其他項目中，有部分產業成因果關係。在衝擊反應分析中，除了設計業在多數指標對本身及其他產業關係不顯著外，製造業與封測業在多數指標對本身及其他產業有顯著程度的影響。在變異數分解分析中，在多數財務指標下，製造業外生性最強，對自身變異的解釋能力高，受其他產業的影響程度相當低。總而言之，DRAM產業上中下游之關聯性比較接近零和的競爭關係，且製造業在整體DRAM產業中為關鍵性的角色。

The purpose of this study is to use the time series method to examine interrelationships (the correlation) of performance among vertical markets of DRAM manufacturing firms of Taiwan. In other words, it aims to investigate whether their link is of a win-loss or profit-share relationship. Resulting data finds that there is no long-term equilibrium relationship among the upper, middle and lower stream of the DRAM industry. During the short-tem period, these industries have been influenced only by themselves in Income before Tax and Operating Income items, while the design and packing industries influence each other in Net Sales and Gross Profit items. From the causality test, there is no lead-lag relationship among the design, packaging and manufacturing industries in the Income before Tax item, but there is a clear relationship in the other three financial items. The empirical results of impulse response functions demonstrate that there are stronger sudden impulses in most finance indexes, except in the design industry. Result from the variance decomposition points out that the manufacturing industry is extrinsically stronger compared to other industries in most financial indexes. In summary, the relationship among these industries is a zero-sum game and the manufacturing industry plays an important role in the DRAM industries.