A matching prior based on the modified profile likelihood in a generalized Weibull stress‐strength model

Bayesian inference of a generalized Weibull stress‐strength model (SSM) with more than one strength component is considered. For this problem, properly assigning priors for the reliabilities is challenging due to the presence of nuisance parameters. Matching priors, which are priors matching the posterior probabilities of certain regions with their frequentist coverage probabilities, are commonly used but difficult to derive in this problem. Instead, we apply an alternative method and derive a matching prior based on a modification of the profile likelihood. Simulation studies show that this proposed prior performs well in terms of frequentist coverage and estimation even when the sample sizes are minimal. The prior is applied to two real datasets. The Canadian Journal of Statistics 41: 83–97; 2013 © 2012 Statistical Society of Canada     

A Small Sample Test for the Equality of Intraclass Correlation Coefficients Under Unequal Family Sizes for Several Populations

The set of all distinct blocks of a BIBD(v,b,r,k,λ) is referred to as the support of the design. In this paper, the family of BIB designs with v=9 and k=3 is studied from the view of possible support sizes, b*'s. A table is constructed of designs with support sizes belonging to {12,18,20,21,…,84}, for minimum possible b in each case and for any larger admissible b. In constructing this table the methods of trade-off and composition of designs are utilized     

A MODEL OF ETHNIC CONFLICT

We present a model of conflict in which discriminatory government policy or social intolerance is responsive to various forms of ethnic activism, including violence. It is this perceived responsiveness—captured by the probability that the government gives in and accepts a proposed change in ethnic policy—that induces individuals to mobilize, often violently, to support their cause. Yet, mobilization is costly and militants have to be compensated accordingly. The model allows for both financial and human contributions to conflict and allows for a variety of individual attitudes (“radicalism”) towards the cause. The main results concern the effects of within‐group heterogeneity in radicalism and income, as well as the correlation between radicalism and income, in precipitating conflict.     

EMERGENCE AND PERSISTENCE OF INEFFICIENT STATES

We present a theory of the emergence and persistence of inefficient states based on patronage politics. The society consists of rich and poor. The rich are initially in power, but expect to transition to democracy, which will choose redistributive policies. Taxation requires the employment of bureaucrats. By choosing an inefficient state structure, the rich may be able to use patronage and capture democratic politics, so reducing the amount of redistribution in democracy. Moreover, the inefficient state creates its own constituency and tends to persist over time. Intuitively, an inefficient state structure creates more rents for bureaucrats than would an efficient one. When the poor come to power in democracy, they will reform the structure of the state to make it more efficient so that higher taxes can be collected at lower cost and with lower rents for bureaucrats. Anticipating this, when the society starts out with an inefficient organization of the state, bureaucrats support the rich, who set lower taxes but also provide rents to bureaucrats. We obtain that the rich–bureaucrats coalition may also expand the size of bureaucracy excessively so as to generate enough political support. The model shows that an equilibrium with an inefficient state is more likely to arise when there is greater income inequality, when bureaucratic rents take intermediate values, and when individuals are sufficiently forward‐looking.     

Financial Globalization and the Governance of Domestic Financial Intermediaries

We model a small open economy in which both domestic financial intermediaries and entrepreneurs face incentive constraints, as in Holmstrom and Tirole (1997) , to study the general equilibrium impact of various types of capital inflows on the efficiency and governance of domestic banks. Banks have an advantage in monitoring firms, but the latter can collude with banks and offer side‐payments to reduce the intensity of monitoring. Opening up to international capital flows makes domestic banks’ capital scarcer relative to uninformed capital, thus increasing the relative cost of monitoring. We show that capital account liberalization has ambiguous effects on the governance of the domestic financial system by sometimes increasing firms’ incentives to collude with banks. We characterize the conditions under which governance is more likely to deteriorate after opening up the capital account, and discuss the effects on investment, productivity and output. We also analyze the effects of foreign direct investment in the corporate and banking sectors. Stylized facts are consistent with the predictions of the model.     

Error rate for testing a contrast after a significant F test

In statistical applications an experimenter often tests a particular contrast after a significant F test for the equality of means. This paper evaluates the overall error rate for this testing .procedure.     

A system for computing joint probabilities from jensen's bivariate f distribution

A system of subroutines is presented for efficient computation of joint probabilities from Jensen's bivariate F distribution. Any valid set of parameters is permitted, whereas previous work was limited to the special case of equal numerator degrees of freedom and equal canonical correlations in the underlying multinormal distribution. The use of joint Probabilities from Jensen's bivariate F distribution is demonstrated via an application to two-way ANOVA without interaction.     

Screening for Multiple Target Detection

We apply statistical selection theory to multiple target detection problems by analyzing the Mahalanobis distances between multivariate normal populations and a desired standard (a known characteristic of a target). We want to achieve the goal of selecting a subset that contains no non target (negative) sites, which entails screening out all non targets. Correct selection (CS) is defined according to this goal. We consider two cases: (1) that all covariance matrices are known; and (2) that all covariance matrices are unknown, including both heteroscedastic and homoscedastic cases. Optimal selection procedures are proposed in order to reach the selection goal. The least favorable configurations (LFC) are found. Tables and figures are presented to illustrate the properties of our proposed procedures. Simulation examples are given to show that our procedures work well. The log-concavity results of the operating characteristic functions are also given.