This article presents a framework for individual and joint tests of si
gnificance employing nonparametric estimation procedures. The proposed
test is based on nonparametric estimates of partial derivatives, is r
obust to functional misspecification for general classes of models, an
d employs nested pivotal bootstrapping procedures. Two simulations and
one application are considered to examine size and power relative to
misspecified parametric models, and to test for the linear unpredictab
ility of exchange-rate movements for G7 currencies.