To infer on functional dependence of regression parameters, a new, factor based bootstrap approach is introduced that is robust under various forms of heteroskedastic error terms. Modeling the functional coefficient parametrically, the bootstrap approximation of an F-statistic is shown to hold...

What does the saving-investment (SI) relation really measure and how should the SI relation be measured? These are two of the most discussed issues triggered by the so called Feldstein-Horioka puzzle. Based on panel data we introduce a new variant of functional coefficient models that allows to...