Novel model specifications that include a time-varying long run component in the dynamics of realized covariance matrices are proposed. The adopted modeling framework allows the secular component to enter the model structure either in an additive fashion or as a multiplicative factor, and to be...

In open pit mining, one must dig a pit, that is, excavate the upper layers of ground before reaching the ore. The walls of the pit must satisfy some geomechanical constraints, in order not to collapse. The question then arises how to mine the ore optimally, that is, how to find the optimal pit....

To study the stability of coalitions in the standard game theoretic model of international environmental agreements, two alternative concepts are used: potential internal stability and core stability. Both concepts make use of the possibility of reallocating payoffs within a coalition through...

We consider multiobjective and parametric versions of the global minimum cut problem in undirected graphs and bounded-rank hypergraphs with multiple edge cost functions. For a fixed number of edge cost functions, we show that the total number of supported non-dominated (SND) cuts is bounded by a...

Nowcasting volatility of financial time series appears difficult with classical volatility models. This paper proposes a simple model, based on an ARMA representation of the log-transformed squared returns, that allows to estimate current volatility, given past and current returns, in a very...

In this paper, we derive Lagrange multiplier and Lagrange multiplier type specification and misspecification tests for vector smooth transition models. We report results from simulation studies in which the size and power properties of the proposed tests in small samples are considered. The...

We propose a new class of multidimensional poverty indices. To aggregate and weight the different dimensions of poverty, we rely on the preferences of the concerned agents rather than on an arbitrary weighting scheme selected by the analyst. The Pareto principle is, therefore, satisfied among...

Recent extensions of the standard Dixit-Stiglitz (1977) model, that go beyond the CES sub-utility assumption, while maintaining monopolistic competition, have mainly emphasized the role of iintrasectoral substitutability. We argue that introducing oligopolistic competition can be an alternative...

Polarization measures, that are used in examining the empirical relationship between ethnic divisions and violent conflict, heavily rely on mechanisms of group identification and often use somewhat arbitrary divisions of a society into ethnic groups. In this paper we construct two new measures...

In an increasing number of empirical studies, the dimensionality measured e.g. as the size of the parameter space of interest, can be very large. Two instances of large dimensional models are the linear regression with a large number of covariates and the estimation of a regression function with...