以DID計量方法分析:新冠肺炎對臺灣印刷電路板產業中上中游之影響

Abstract

自COVID-19大流行爆發以來，全球經濟面臨前所未有的風險與機遇。印刷電路板（PCB），被稱為「電子產業之母」，是組裝電子元件的基礎，通過電路板上的銅箔導線連接並傳遞信號和電流。臺灣的PCB產業已經發展成熟，擁有完整的供應鏈，涵蓋上游材料如玻纖布和銅箔基板，到下游的電子應用產品。本文旨在探討COVID-19疫情如何改變PCB產業的管理決策。我們預期，隨著遠程辦公和線上教育的興起，COVID-19疫情將推動PCB產業中計算和通訊設備等電子產品的全球需求激增。 與此同時，臺灣的國防產業主要由政府需求驅動，受全球經濟波動的影響相對較小，因此在疫情期間可能更具韌性。該產業在2017年至2022年間從「5+2產業創新政策」轉變為「六大核心戰略產業」之一，強化了在航空、造船等領域的自主國防能力。在政府強力支持下，國防產業的發展受疫情衝擊較小，成為分析臺灣PCB產業的良好對照組。 本文採用了差異中之差異法（difference-in-differences，以下簡稱DID）研究設計來分析COVID-19疫情對臺灣PCB產業（實驗組）管理決策的影響，並以受影響較小的臺灣國防產業作為控制組。前期處理期間為2016年第二季度至2020年第一季度，後期處理期間為2020年第二季度至2023年第四季度。我們具體檢視了銷售額、資產報酬率（ROA）、股東權益報酬率（ROE）、研發費用（R&D）和資本支出（CAPEX）的水準與變化。DID分析顯示，COVID-19疫情與PCB產業的銷售成長率與資本支出成長率呈負相關，但與研究與開發費用率呈正相關。且研究結果在不同檢驗中具有穩健性。

Since the COVID-19 pandemic started, the global economy has faced unprecedented risks and opportunities. The Printed Circuit Board (PCB), known as the "Mother of the Electronics Industry," is the foundation for assembling electronic components, enabling them to connect and transmit signals and current through copper foil traces on the circuit board. Taiwan's PCB industry is well-established, with a complete supply chain from upstream materials, such as fiberglass cloth and copper foil substrates, to downstream electronic application products. This master's thesis aims to investigate how the COVID-19 pandemic has changed the managerial decision-making of the PCB industry. We expect that with the rise of remote work and online education, the COVID-19 pandemic will create a spike in global demand for electronic products like computing and communication equipment for the PCB industry. In contrast, we expect that the defense industry, driven mainly by government defense demand, is less affected by global economic fluctuations and, thus, by the COVID-19 pandemic. Specifically, Taiwan's defense industry has transformed, evolving from the "5+2 Industrial Innovation Policy" to one of the "Six Core Strategic Industries" between 2017 and 2022. This policy has accelerated the development of self-reliant national defense in the aviation and shipbuilding sectors. We employ a difference in differences (DID) research design to analyze the impact of the COVID-19 pandemic on the managerial decision-making of Taiwan's PCB industry (treated group) using the potentially unaffected Taiwan's defense industry as the control group. The pre-treatment period is from 2016 Q2 to 2020 Q1, while the post-treatment period is from 2020 Q2 to 2023 Q4. Specifically, we examine both the level and changes in sales, return on assets (ROA), return on equity (ROE), research and development expenses (R&D), and capital expenditure (CAPEX). Our DID analysis demonstrates that the COVID-19 pandemic is negatively associated with sales and sales growth for the PCB industry, whereas it is positively associated with R&D. Our results are robust to alternative tests.