Policymakers and mainstream economists expressed concerns over the distributional impacts of monetary policy after the emergence of so-called Unconventional Monetary Policies (UMP) after the subprime and Eurozone crises (2007-2009). This topic, however, is not new for post-Keynesian authors. At least since Keynes’s ‘euthanasia of the rentier,’ this school of thought has dedicated numerous works to this issue. This paper focuses on one of these works, the "fair" interest rate developed by Luigi Pasinetti, which came to be known later as the Pasinetti Index (PI). After an incursion into the history of this idea, the paper develops an econometric analysis of the connection between the PI, the functional income distribution, and the aggregate demand for the US from 1968 to 2022 using a threshold vector autoregressive model. The results indicate that the US economy has experienced different distributive regimes associated with changes in monetary policy. As a result, the economy has moved from the stable but volatile Keynesian era toward a less volatile but uncertain period in which monetary policy is employed to protect the income and wealth of rentiers. Moreover, the work also showed that switches to rentier-biased regime are highly detrimental to aggregate demand and functional income distribution.