Nutrition and economic growth in South Africa: a threshold co-integration approach

Purpose - The purpose of this paper is to examine asymmetric co-integration effects between nutrition and economic growth for annual South African data from the period 1961-2013. Design/methodology/approach - The authors deviate from the conventional assumption of linear co-integration and pragmatically incorporate asymmetric effects in the framework through a fusion of the momentum threshold autoregressive and threshold error correction (MTAR-TEC) model approaches, which essentially combines the adjustment asymmetry model of Enders and Silkos (2001); with causality analysis as introduced by Granger (1969); all encompassed by/within the threshold autoregressive (TAR) framework, a la Hansen (2000). Findings - The findings obtained from the study uncover a number of interesting phenomena for the South Africa economy. First, in coherence with previous studies conducted for developing economies, the authors establish a positive relationship between nutrition and economic growth with an estimated income elasticity of nutritional intake of 0.15. Second, the authors find bi-direction causality between nutrition and economic growth with a stronger causal effect running from nutrition to economic growth. Lastly, the authors find that in the face of equilibrium shocks to the variables, policymakers are slow to responding to deviations of the variables from their co-integrated long run steady state equilibrium. Originality/value - In the study, the authors make a novel contribution to the literature by exploring asymmetric modelling in the correlation between nutrition intake and economic growth for the exclusive case of South Africa.