A Comparison of Unit-Root Test Criteria

During the past 15 years, the ordinary least squares estimator and the corresponding pivotal statistic have been widely used for testing the unit-root hypothesis in autoregressive processes. Recently, several new criteria, based on maximum likelihood estimators and weighted symmetric estimators, have been proposed. In this article, we describe several different test criteria. Results from a Monte Carlo study that compares the power of the different criteria indicate that the new tests are more powerful against the stationary alternative. Of the procedures studied, the weighted symmetric estimator and the unconditional maximum likelihood estimator provide the most powerful tests against the stationary alternative. As an illustration, the weekly series of one-month treasury-bill rates is analyzed.     

The Dynamics of Income Growth and Poverty: Evidence from Districts in India

This article examines the dynamics of the income‐distribution pattern in India during the post‐1991 economic reforms. It considers district‐level per‐capita income data across agriculture, manufacturing, services, and various constituent sub‐sectors, and finds evidence in favour of a uniform process of growth across sectors and regions, which has helped to reduce poverty. In particular, the article finds that growth in agricultural income and access to finance are important for this.     

Family and neighborhood sources of socioeconomic inequality in children’s achievement

We examined family and neighborhood sources of socioeconomic inequality in children’s reading and mathematics achievement using data from the 2000–2001 Los Angeles Family and Neighborhood Survey. To describe inequality in achievement scores, we used Gini coefficients and concentration indices and multilevel regression models. We found no inequality in children’s achievement by family income when other variables in the model were held constant. Mother’s reading scores and average neighborhood levels of income accounted for the largest proportion of inequality in children’s achievement. Neighborhood economic status appears to be strongly associated with children’s skills acquisition.     

DO TERRORIST ATTACKS IMPACT EXCHANGE RATE BEHAVIOR? NEW INTERNATIONAL EVIDENCE

This study examines whether terrorist attacks affect bilateral exchange rates. Using historical 10‐minute exchange rate data for 21 countries' currency vis‐à‐vis the U.S. dollar, we show that exchange rate returns of all countries are statistically significantly affected by terrorist attacks. Some exchange rates appreciate and some depreciate following a terrorist attack, some currencies experience exchange rate reversals while others experience a persistent effect. Generally, the effect declines but persists as terrorist attacks become stale information. (JEL F31, F37)     

On the Extinction Time of a Continuous time Markov Branching Process

Several authors have studied and derived bounds for the mean extinction time of a discrete branching process. In this note, we obtain the mean and variance of the extinction time, given extinction of a continuous time Markov branching process. We also obtain bounds for the mean extinction time in terms of moments of the offspring distribution.     

A new unit root test with two structural breaks in level and slope at unknown time

In this paper, we propose a new augmented Dickey–Fuller-type test for unit roots which accounts for two structural breaks. We consider two different specifications: (a) two breaks in the level of a trending data series and (b) two breaks in the level and slope of a trending data series. The breaks whose time of occurrence is assumed to be unknown are modeled as innovational outliers and thus take effect gradually. Using Monte Carlo simulations, we show that our proposed test has correct size, stable power, and identifies the structural breaks accurately.     

A series of group divisible designs

Bose and Shrikhande C19763 proved that if D(m, k, ?) is a Baer subdesign of another SBIBD D₁ (v₁, k₁ ?), k₁>k, then it also contains a complementary subdesign D^* which is symmetric GDD, D^* (v^*, k^*; ?-1, ?; m, n). Utilising this, we give a necessary condition for a SBIBD D to be a Baer subdesign of D₁ and also give the parameters. Some GD designs are constructed.