Pao Li Chang

How accurate are confidence intervals for impulse responses in large VAR models

Abstract We study the finite-sample accuracy and average length of pointwise confidence intervals for impulse responses in vector autoregressive models with many variables and many lags. Our results complement existing simulation evidence based on much simpler bivariate models.

L S Penrose's limit theorem: Tests by simulation

LS Penrose’s limit theorem (PLT) – which is implicit in Penrose [5, p. 72] and for which he gave no rigorous proof – says that, in simple weighted voting games, if the number of voters increases indefinitely while existing voters retain their weights and the relative quota is pegged, then – under certain conditions – the ratio between the voting powers of any two voters converges to the ratio between their weights. Lindner and Machover [3] prove some special cases of PLT; and conjecture that the theorem holds, under rather general conditions, for large classes of weighted voting games, various values of the quota, and with respect to several measures of voting power. We use simulation to test this conjecture. It is corroborated w.r.t. the Penrose–Banzhaf index for a quota of 50% but not for other values; w.r.t. the Shapley–Shubik index the conjecture is corroborated for all values of the quota (short of 100%).

TRADE AND DIVERGENCE IN EDUCATION SYSTEMS

This article presents a theory on the endogenous choice of education policy and the two‐way causal relationship between trade and education systems. A countrys education system determines its talent distribution and comparative advantage; the possibility of trade by raising the returns to the sector of comparative advantage in turn induces countries to further differentiate their education systems and reinforces the initial pattern of comparative advantage. Specifically, the Nash equilibrium choice of education systems by two countries interacting strategically are necessarily more divergent than their autarky choices, and yet less than what is socially optimal for the world.

Trade and Divergence in Education Systems

This article presents a theory on the endogenous choice of education policy and the two‐way causal relationship between trade and education systems. A countrys education system determines its talent distribution and comparative advantage; the possibility of trade by raising the returns to the sector of comparative advantage in turn induces countries to further differentiate their education systems and reinforces the initial pattern of comparative advantage. Specifically, the Nash equilibrium choice of education systems by two countries interacting strategically are necessarily more divergent than their autarky choices, and yet less than what is socially optimal for the world.

A Misspecification-Robust Impulse Response Estimator

Impulse response analysis is typically conducted by fitting an autoregression model to a time series and calculating the moving average coefficients implied by the estimated autoregression model. If the autoregression specification is incorrect for the series, this approach may fail to capture important features of the impulse response function, because the parsimonious autoregression specification severely limits the possible shape and persistence of the implied impulse response function. This paper proposes an alternative estimator that is asymptotically valid yet is less susceptible to model misspecifications in small samples. We establish the consistency of the proposed estimator and demonstrate its small sample advantages by Monte Carlo simulations.

Country Image and International Trade

We study the impact of country image on international trade flows. We find that a one percentage point increase in the positive response ratio – the proportion of people in the importing country who view the exporting country positively – is associated with at least a one percent increase in the aggregate trade flow. By disaggregating trade flows by type of goods, we also find that both homogeneous and differentiated goods are positively affected by better country image and that the impact of country image tends to be larger when more substitutes are available in the international market.