Investment, Tobin's Q, and Cash Flow Across Time and Frequencies
使用连续小波工具，同时从不同频率和时间维度分析投资、托宾Q与现金流的关系，发现Q对中长期投资更重要，现金流对商业周期频率投资更重要，且投资-Q敏感性随时间下降，投资-现金流敏感性在商业周期频率下降但中长期稳定。
Abstract The investment literature has long acknowledged the time‐ and frequency‐varying dynamics of the relationship between investment, Tobin's Q and cash flow. In this paper, we use continuous wavelet tools to estimate and assess the relationship between these variables simultaneously at different frequencies and over time. We find that (i) Q and cash flow are complementary sources of information for investment, the former being more important for firms’ investment decisions in the medium‐to‐long run and the latter at business cycles frequencies; and (ii) investment‐Q sensitivity declines over time at all frequencies, while investment–cash flow sensitivity declines at business cycles frequencies but remains largely stable over the medium‐to‐long run.