For interpolating kernel machines, minimizing the norm of the ERM solution minimizes stability
Authors: Akshay Rangamani, Lorenzo Rosasco, Tomaso Poggio
Keywords: Stability, Linear Regression, Kernel Regression, Cross Validation Leave One Out Stability, Minimum norm solutions, Interpolation, Double Descent
Abstract: We study the average CV Leave One Out stability of kernel ridge-less regression and derive corresponding risk bounds. We show that the interpolating solution with minimum norm minimizes a bound on CV Leave One Out stability, which in turn is controlled by the condition number of the empirical kernel matrix. The latter can be characterized in the asymptotic regime where both the dimension and cardinality of the data go to infinity. Under the assumption of random kernel matrices, the corresponding test error should be expected to follow a double descent curve.