Change point tests based on U-statistics with applications in reliability

We consider the problem of testing the null hypothesis of no change against the alternative of exactly one change point. The proposed tests are based on generalized two-sample U-statistic processes. We drive the limiting null distributions of the proposed tests. Some applications in Statistical Reliability are given. This research was supported by an NSERC Canada grant at the University of Alberta. Part of this research was done while visiting the University of Alberta supported by the NSERC Canada grant of the first author.     

Testing whetherF is more IFR thanG

A distributionF is said to be “more IFR” than another distributionG ifG ⁻¹ F is convex. WhenF(0) =G(0) = 0, the problem of testingH ₀ :F(x) =G (θx) for someθ > 0 andx ⩾ 0, against the alternativeH _A:F is more IFR thanG, is considered in this paper. Both cases, whenG is completely specified (one-sample case) and when it is not specified but a random sample form it is available (two-sample case) are considered. The proposed tests are based onU-statistics. The asymptotic relative efficiency of the tests are compared with several other tests and the test statistics remain asymptotically normal under certain dependency assumptions. Research supported in part by a grant from the US Air Force Office of Scientific Research.     

On testing for independence against right tail increasing in bivariate models

A random variableY is right tail increasing (RTI) inX if the failure rate of the conditional distribution ofX givenY>y is uniformly smaller than that of the marginal distribution ofX for everyy0. This concept of positive dependence is not symmetric inX andY and is stronger than the notion of positive quadrant dependence. In this paper we consider the problem of testing for independence against the alternative thatY is RTI inX. We propose two distribution-free tests and obtain their limiting null distributions. The proposed tests are compared to Kendall's and Spearman's tests in terms of Pitman asymptotic relative efficiency. We have also conducted a Monte Carlo study to compare the powers of these tests.Research supported by an NSERC Canada operating grant at the University of Alberta.Part of this research was done while visiting the University of Alberta supported by the NSERC Canada grant of the first author.     

Targeting public goods to the poor in a segregated economy: An empirical analysis of central mandates in rural India

While local governments are increasingly being vested with control over funds for public goods, concern over the capture of decentralized funds by local elites has led decentralization to be combined with central mandates which require a certain proportion of funds to directly benefit the poor. If local capture is pervasive, however, central mandates may not be effective. Despite the popularity of this combination of decentralization and centralized control, there is little empirical evidence which separately identifies their effect on investment in public goods, and hence assesses the effectiveness of central mandates. This paper provides such evidence, using data collected by the authors for the North Indian state of Punjab, an economy where economic conditions facilitate such an analysis. We find that central mandates are effective, enhancing intra-village equality in expenditure on public goods. This finding informs the debate on the equity effects of centralized versus decentralized programs.     

Schooling,wages and profits: Negative pecuniary externalities from schooling and their consequences for schooling investments

This paper tests the hypothesis that the schooling of the poor reduces profits for landowners, and that such negative pecuniary externalities in turn adversely affect schooling investments made by local governments. A theoretical model of occupational choice in the presence of credit and labor market constraints, combined with existing political economy models of the delivery of local public goods delivers such a result. This hypothesis is tested using household data from India. The empirical analysis shows that profits are reduced by the schooling of the poor and that this is primarily because of the effect of schooling on wages. It also shows that the negative effect of wages on profits reduces government provided schooling inputs.