We have conducted a multiscale analysis of system behavior for improvement of infection control in and among hospitals, other care facilities and their relationships to community settings. Our analysis identifies key leverage points for intervention to improve the quality of healthcare systems. In particular, it reveals intervention points that are not currently being addressed. While today the...

The paper develops a system dynamics simulation model to understand the dynamics of immunisation with the aim of aiding decision making process by proposing policies that would enhance immunisation utilization. The model is designed with the intent to show how particular variables influence immunisation demand and coverage rather than predict immunisation coverage rates. The paper applies syste...

changes in credit risk may arise when either the value or the risk of corporate assets changes. changes in the equity value associated with the changes in the asset value and changes in asset risk can be characterized into potentially countervailing direct and indirect effects. the indirect effect of risk on equity value is a function of factors that affect the debt value of including leverage,...

changes in credit risk may arise when either the value or the risk of corporate assets changes. changes in the equity value associated with the changes in the asset value and changes in asset risk can be characterized into potentially countervailing direct and indirect effects. the indirect effect of risk on equity value is a function of factors that affect the debt value of including leverage,...

An efficient Bayesian estimation using a Markov chain Monte Carlo method is proposed in the case of a multivariate stochastic volatility model as a natural extension of the univariate stochastic volatility model with leverage and heavy-tailed errors. Note that we further incorporate cross-leverage effects among stock returns. Our method is based on a multi-move sampler that samples a block of l...

Species tree methods are now widely used to infer the relationships among species from multilocus data sets. Many methods have been developed, which differ in whether gene and species trees are estimated simultaneously or sequentially, and in how gene trees are used to infer the species tree. While these methods perform well on simulated data, less is known about what impacts their performance ...

Hedge fund managers are often compensated via management fees on the assets under management (AUM) and incentive fees indexed to the high-water mark (HWM). We develop an analytically tractable model of hedge fund leverage and valuation where the manager maximizes the present value (PV) of future management and incentive fees from current and future managed funds. By leveraging on an alpha strat...

Crowdsourcing is an increasingly popular phenomenon where companies solicit the help of the public in helping accomplish some of the activities commonly performed by employees or contractors. These activities can range from solving scientific problems that baffle the in-house experts to repetitive and boring tasks that are deemed too mundane for the employees. Other activities include content g...

This paper investigates the link between the optimal level of nonfinancial firms’ leverage and macroeconomic uncertainty. We develop a structural model of a firm’s value maximization problem that predicts that as macroeconomic uncertainty increases the firm will decrease its optimal level of borrowing. We test this proposition using a panel of non–financial US firms drawn from the COMPUSTAT qua...

We consider the long memory and leverage properties of a model for the conditional variance V 2 t of an observable stationary sequence Xt, where V 2 t is the square of an inhomogeneous linear combination of Xs, s < t, with square summable weights bj . This model, which we call linear ARCH (LARCH), specializes, when V 2 t depends only on Xt−1, to the asymmetric ARCH model of Engle (1990), and, w...