We develop general econometric models of ascending (English) auctions which allow for both bidder asymmetries as well as common and/or private value components in bidders' underlying valuations. We show that the equilibrium inverse bid functions in each round of the auction are implicitly deened (pointwise) by a system of nonlinear equations, so that conditions for the existence and uniqueness ...

Most existing econometric models such as ARCH(q) and GARCH(p,q) take into account heteroskedasticity (non-stationarity) of time series. However, the original ARCH(q) and GARCH(p,q) models do not take into account the asymmetry of the market’s response to positive and to negative changes. Several heuristic modifications of ARCH(q) and GARCH(p,q) models have been proposed that take this asymmetry...

Joint degree vectors give the number of edges between vertices of degree i and degree j for 1 6 i 6 j 6 n − 1 in an n-vertex graph. We find lower and upper bounds for the maximum number of nonzero elements in a joint degree vector as a function of n. This provides an upper bound on the number of estimable parameters in the exponential random graph model with bidegree-distribution as its suffici...

We review regression models for count time series. We discuss the approach which is based on generalized linear models and the class of integer autoregressive processes. The generalized linear models framework provides convenient tools for implementing model fitting and prediction using standard software. Furthermore, this approach provides a natural extension to the traditional ARMA methodolog...

The peripheral auditory system is a complex ensemble of mechanical and neural structures that have a profound influence on how we perceive sounds. As more became known about the physiology of these structures, computational models emerged to simulate their functions. Auditory models are now widely used in psychoacoustics to predict phenomena such as masking, loudness, pitch, roughness, etc. A v...

In many reliability applications, there may not be a unique plausible scale in which to measure time to failure or assess performance. This is especially the case when several measures of usage are available on each unit. For example, the age, the total number of flight hours, and the number of landings are usage measures that are often considered important in aircraft reliability. Similarly, i...