Abstract
Variable selection is the issue of major concern in practical regressions. This note provides a simple and efficient method to examine the robustness of predictor variables in cross-country economic growth models. Our results confirm the general findings of Sala-i-Martin et al. (2004), indicating the importance of a number of same predictor variables. In addition, we also identify that some other variables are associated with economic growth.
Funding
This research is partially supported by the National Natural Science Foundation of China [grant number 71171075], [grant number 71221001], and [grant number 71031004].
Notes
1 In empirical economy, a precursor to apply boosting methods is Kostov (Citation2010). Kostov (Citation2010) applies a component-wise gradient boosting algorithm to deal with the issue of spatial weight matrix uncertainty. The basic idea is to choose the most ‘appropriate’ spatial weight matrix amongst a predetermined set of weight matrixes.
2 The function f(.) can be expressed in different forms, e.g. linear components, nonparametric smooth components and spatial effects and interaction surfaces (Kneib et al., Citation2009).
3 Kneib et al. (Citation2009) point out that ‘the variable selection procedure from boosting algorithm does not automatically choose the most significance variables’.
4 In this article we consider only 86 countries since there have some missing value for Iceland and Fiji. We are grateful to the authors for sharing the data.
5 All the computations are carried out using the mboost package in R Project (see Hofner et al., Citation2012).