Deockhyun Ryu

Spillover Effects of Public Capital Stock Using Spatial Frontier Analyses: A First Look at the Data

This paper aims to investigate spillover effects of public capital stock in a production function model that accounts for spatial dependencies. Although there are a number of studies that estimate the output elasticity of public capital stock, they suffer from a failure to refine the output elasticity of public capital stock as well as to account for spillover effects of the public capital stock on the production efficiency when such spatial dependencies exist. For this purpose we employ a spatial autoregressive stochastic frontier model and analyze estimates with a time-varying spatial weights matrix. Using data for 21 OECD countries from 1960 to 2001, we found that spillover effects can be an important factor explaining variations in technical inefficiency across countries as well as discrepancies among various levels of output elasticity of public capital stock in traditional production function approaches.

How to Measure Spillover Effects of Public Capital Stock: A Spatial Autoregressive Stochastic Frontier Model

This paper aims to investigate spillover e?ects of public capital stock in a production function model that accounts for spatial dependencies. In many settings, ignoring spatial dependency yields inefficient, biased and inconsistent estimates in cross country panels. Although there are a number of studies aiming to estimate the output elasticity of public capital stock, many of those fail to reach a consensus on refining the elasticity estimates. We argue that accounting for spillover effects of the public capital stock on the production efficiency and incorporating spatial dependences are crucial. For this purpose we employ a spatial autoregressive stochastic frontier model based on a number of specifications of the spatial dependency structure. Using the data of 21 OECD countries from 1960 to 2001, we estimate a spatial autoregressive stochastic frontier model and derive the mean indirect marginal effects of public capital stock, which are interpreted as spillover effects. We found that spillover effects can be an important factor explaining variations in technical ineffciency across countries as well as in explaining the discrepancies among various levels of output elasticity of public capital stock in traditional production function approaches.

Nonstationarity and Stochastic Stability of Relative Income Clubs

The recent literature on “convergence” of cross‐country per capita incomes has been dominated by the two hypotheses of “global convergence” and “club‐convergence,” pertaining to limits of estimated income distribution dynamics. Utilizing a new measure of “stochastic stability,” we establish two stylized facts regarding short‐ and medium‐term distribution dynamics. The first is non‐stationarity of transition dynamics, in the sense of changing transition kernels, and the second is emergence, disappearance, and re‐emergence of a “stochastically stable” middle income group. This middle income group emerges as the gap between rich and poor clubs gets larger, and it changes the dynamics of transition to and from the rich and poor clubs, eventually narrowing the gap between the poor and rich as the middle club vanishes. Analyzing the stochastic stability of middle‐income groups is thus a first step toward understanding higher‐order dynamics of narrowing or widening of the gap between rich and poor countries.