Theories such as Minsky's financial instability hypothesis or New Keynesian financial accelerator models assign a key role to financial factors in business cycle dynamics. We present descriptive statistics and a simple estimation framework to examine the financial-real interaction mechanisms that are at the core of these theories. Specifically, we examine cycle frequencies in seven OECD countries over the period 1970 to 2015, and find that interest rates, business debt, and household debt exhibit cycle lengths of 4-6, 8-11, and 14-26 years, respectively. We then estimate bivariate VAR models which provide evidence for financialreal interaction mechanisms, (i) at high frequencies between interest rates and GDP, and (ii) at low frequencies between business debt and GDP. In contrast, there is no evidence for a cycle mechanism between household debt and GDP.