This article explores the relationship between labor costs and price inflation under two conditions. Firstly, with linear assumption and classical techniques. Secondly, without assuming linearity, by a novel non-parametric machine learning method, namely gradient boosting. With quarterly data...

Up to now, powerful outlier robust tests for linear models are based on M-estimators and are quite complicated. On the other hand, the simple robust classical sign test usually provides very bad power for certain alternatives. We present a generalization of the sign test which is similarly easy...

We study a nonlinear two-way fixed effects panel model that allows for unobserved individual heterogeneity in slopes (interacting with covariates) and (unknown) flexibly specified link function. The former is particularly relevant when the researcher is interested in the distributional causal...

I derive simple, flexible strategies for difference-in-differences settings where the nature of the response variable may warrant a nonlinear model. In addition to covering the case of common treatment timing, I allow for staggered interventions, with and without covariates. Under an index...

The equation x^a+y^b+z^c=m in real numbers represents a group of Nonlinear Multi-Agent Systems, is an ill-posed problem and can be used in physical sciences and social sciences. This article introduces some Equivalence-Conditions, Existence-Conditions and properties of xa+yb+zc=m in real...