The Association Between Investment Opportunity Set Proxies and Realized Growth
检验了多种投资机会集代理变量（如账面市值比、资本支出比率）与公司后续实际增长的相关性，发现研发强度和市盈率比率与增长无稳定关联，对选择有效代理变量有参考价值。
Realized growth can be viewed as a proxy for the unobservable investment opportunity set (IOS) of the firm, and provides a benchmark against which IOS proxy variables can be compared. Results from such a comparison indicate that many of the variables from earlier studies, including book‐to‐market measures and capital expenditure to assets ratios are consistently correlated with subsequently realized growth. However, R&D intensity and E/P ratios do not exhibit any consistent association with subsequent growth indicating that they may not be valid IOS proxies.