Olaf Posch

Measuring Convergence Using Dynamic Equilibrium Models: Evidence from Chinese Provinces

We propose a model to study economic convergence in the tradition of neoclassical growth theory. We employ a novel stochastic set-up of the Solow (1956) model with shocks to both capital and labor. Our novel approach identifies the speed of convergence directly from estimating the parameters which determine equilibrium dynamics. The inference on the structural parameters is done using a maximum-likelihood approach. We estimate our model using growth and population data for China’s provinces from 1978 to 2010. We report heterogeneity in the speed of convergence both across provinces and time. The Eastern provinces show a higher tendency of convergence, while there is no evidence of convergence for the Central and Western provinces. We find empirical evidence that the speed of convergence decreases over time for most provinces.

On the Estimation of the Volatility-Growth Link

It is common practice to estimate the volatility-growth link by specifying a standard growth equation such that the variance of the error term appears as an explanatory variable in this growth equation. The variance in turn is modelled by a second equation. Hardly any of existing applications of this framework includes exogenous controls in this second variance equation. Our theoretical findings suggest that the absence of relevant explanatory variables in the variance equation leads to a biased and inconsistent estimate of the volatility-growth link. Our simulations show that this effect is large. Once the appropriate controls are included in the variance equation consistency is restored. In short, we suggest that the variance equation must include relevant control variables to estimate the volatility-growth link.

Delays in Public Goods

In this paper, we analyze the consequences of delays and cost overruns typically associated with the provision of public infrastructure in the context of a growing economy. Our results indicate that uncertainty about the arrival of public capital can more than offset its positive spillovers for private-sector productivity. In a decentralized economy, unanticipated delays in the provision of public capital generate too much consumption and too little private investment relative to the first-best optimum. The characterization of the first-best optimum is also affected: facing delays in the arrival of public goods, a social planner allocates more resources to private investment and less to consumption relative to the first-best outcome in the canonical model (without delays). The presence of delays also lowers equilibrium growth, and leads to a diverging growth path relative to that implied by the canonical model. This suggests that delays in public capital provision may be a potential determinant of cross-country differences in income and economic growth.