This article investigates the strength of empirical evidence for various growth theories when there is model uncertainty with respect to the correct growth model. Using model averaging methods, we find little evidence that so-called fundamental growth theories play an important role in explaining aggregate growth. In contrast, we find strong evidence for macroeconomic policy effects and a role for unexplained regional heterogeneity, as well as some evidence of parameter heterogeneity in the aggregate production function. We conclude that the ability of cross-country growth regressions to adjudicate the relative importance of alternative growth theories is limited. Copyright � 2008 The Author(s).

This article investigates the strength of empirical evidence for various growth theories when there is model uncertainty with respect to the correct growth model. Using model averaging methods, we find little evidence that so-called fundamental growth theories play an important role in explaining aggregate growth. In contrast, we find strong evidence for macroeconomic policy effects and a role for unexplained regional heterogeneity, as well as some evidence of parameter heterogeneity in the aggregate production function. We conclude that the ability of cross-country growth regressions to adjudicate the relative importance of alternative growth theories is limited.

This paper introduces the structural threshold regression (STR) model that allows for an endogenous threshold variable as well as for endogenous regressors. This model provides a parsimonious way of modeling nonlinearities and has many potential applications in economics and finance. Our framework can be viewed as a generalization of the simple threshold regression framework of Hansen (2000, Econometrica 68, 575–603) and Caner and Hansen (2004, Econometric Theory 20, 813–843) to allow for the endogeneity of the threshold variable and regime-specific heteroskedasticity. Our estimation of the threshold parameter is based on a two-stage concentrated least squares method that involves an inverse Mills ratio bias correction term in each regime. We derive its asymptotic distribution and propose a method to construct confidence intervals. We also provide inference for the slope parameters based on a generalized method of moments. Finally, we investigate the performance of the asymptotic approximations using a Monte Carlo simulation, which shows the applicability of the method in finite samples.

SUMMARY Barro and McCleary (2003, Religion and economic growth across countries. American Journal of Sociology 68: 760–781) is a key research contribution in the new literature exploring the macroeconomic effects of religious beliefs. This paper represents an effort to evaluate the strength of their claims. We evaluate their results in terms of replicability and robustness. Overall, their analysis generally meets the standard of statistical replicability, though not perfectly. On the other hand, we do not find that their results are robust to changes in their baseline statistical specification. When model‐averaging methods are employed to integrate information across alternative statistical specifications, little evidence survives that religious variables help to predict cross‐country income differences. Copyright © 2011 John Wiley & Sons, Ltd.

We employ a structural threshold regression methodology to investigate the heterogeneous effects of debt on growth using public debt as a threshold variable as well as several other plausible variables. Our methodology allows us to address parameter heterogeneity that characterizes cross-country growth data and at the same time account for endogeneity. We find strong evidence for threshold effects based on democracy, which implies that higher public debt results in lower growth for countries in the Low-Democracy regime. Our results are consistent with the presence of parameter heterogeneity in the cross-country growth process due to fundamental determinants of economic growth proposed by the new growth theories.