The Impact of Uncertainty Shocks under Measurement Error: A Proxy SVAR Approach

A growing literature considers the impact of uncertainty using SVAR models that include proxies for uncertainty shocks as endogenous variables. In this paper, we consider the impact of measurement error in these proxies on the estimated impulse responses. We show via a Monte Carlo experiment that measurement error can result in attenuation bias in impulse responses. In contrast, the proxy SVAR that uses the uncertainty shock proxy as an instrument does not suffer from this bias. Applying this latter method to the Bloom (2009) data set results in impulse responses to uncertainty shocks that are larger in magnitude and more persistent than those obtained from a recursive SVAR.     

Vietnam's Agriculture: Processes of Rich Peasant Accumulation and Mechanisms of Social Differentiation

Vietnam's agrarian transition is reviewed and, against the World Bank view that land markets in Vietnam have been pro-poor, it is suggested that access to land has become stratified within specific provinces, districts and communes. Aggregate data and field research both demonstrate that the technical coefficients of production differ between farms when grouped according to a proxy for wealth, and that this is correlated with productivity per unit of land. It is therefore argued that there are emerging differences between farms that reflect divergence in the scale of production. At the same time, when grouped according to wealth there are differences between farms in terms of crop mix, the degree of market integration, and the extent of rural diversification. Holistic examination of the evidence suggests that Vietnam has an emergent group of rich peasants with relatively larger landholdings, amounts of capital stock, and use of hired labour-power; and higher yields per unit of land, a greater degree of market integration, and more marked productive diversification. This class can be set beside a numerically preponderant class of relatively small peasants, with smaller landholdings and amounts of capital, a heavier reliance on family labour, lower yields per unit of land, and less market integration and diversification. The evidence further demonstrates the rapid growth of a class of rural landless who are largely separated from the means of production, who survive by intermittently selling their labour, and who are the poorest segment of rural society.     

Changing Impact of Shocks: A Time-Varying Proxy SVAR Approach

In this paper, we extend the Bayesian Proxy vector autoregression (VAR) model to incorporate time variation in the parameters. A novel Metropolis-within-Gibbs sampling algorithm is provided to approximate the posterior distributions of the model's parameters. Using the proposed algorithm, we estimate the time-varying effects of taxation shocks in the United States and the United Kingdom and find evidence for a decline in the impact of these shocks on output growth.