Using a hyperbolic cross to solve non-linear macroeconomic models

The paper presents a sparse grid approximation method based on the hyperbolic cross and applies it to solve non-linear macroeconomic models. We show how the standard hyperbolic cross can be extended to give greater control over the approximating grid and we discuss how to implement an anisotropic hyperbolic cross. Applying the approximation method to four macroeconomic models, we establish that it delivers a level of accuracy on par or better than Smolyak's method and that it can produce accurate approximations using fewer points than Smolyak's method.