中文摘要
企业股票市值的实际增长率已从1958年至1980年间年均接近0%，上升至1980年至今的5.2%。这一变化与始于1980年的市场势力和利润上升同时发生。本文提出以利润（收益）而非股息为基础分解企业价值。由于企业平均仅将一半利润用于派发股息，股息并不能很好地衡量企业绩效。我将所有上市公司价值上升的来源分解为以下几类：(1) 主观且无风险的贴现因子；(2) 预期未来利润；(3) 股东权益（留存收益）。研究发现，价值上升的20%源于贴现因子，80%源于利润（其中当前及预期未来利润占45%，留存收益占35%）。我构建了一个企业具有市场势力的经济一般均衡模型，进行反事实分析并评估其福利影响，目标是研究竞争政策的影响。如果当前市场势力降至1980年的水平，平均股票市值将降低45%。相反，如果市场势力自1980年起从未上升，平均股票市值将降低80%。
Abstract
Abstract The real growth of the stock market value of firms has increased from close to 0% on average per year between 1958 and 1980, to 5.2% between 1980 and today. This change coincides with the rise of market power and profits, starting in 1980. This paper proposes to decompose the value of firms based on profits (earnings) rather than dividends. Because firms on average pay out only half of profits in dividends, dividends poorly measure firm performance. I decompose the sources of the rise of the value of all publicly traded firms into the following categories: (1) the subjective and risk-free discount factor, (2) expected future profits, and (3) shareholder equity (retained earnings). I find that 20% of the rise is due to the discount factor and 80% is due to profits (45% current and future expected profits; 35% retained earnings). I build a general equilibrium model of the economy where firms have market power; I perform counterfactuals and evaluate the welfare implications. The objective is to study the impact of competition policy. If market power today dropped to the level of 1980, average stock market values would be 45% lower. Instead, if market power had never increased in 1980, the average stock values would be 80% lower.