It has been long recognized that an exhaustible-resource monopsonist faces a commitment problem similar to that of a durable-good monopolist. Indeed, Hörner and Kamien (2004) demonstrate that the two problems are formally equivalent under full commitment. We show that there is no such equivalence in the absence of commitment. The existence of a choke price at which the monopsonist adopts the su...

With the high accident rate of civil aviation, medical resource inventory becomes more important for emergency management at the airport. Meanwhile, medical products usually are time-sensitive and short lifetime. Moreover, we find that the optimal medical resource inventory depends on multiple factors such as different risk preferences, the material shelf life and so on. Thus, it becomes very c...

This paper presents a spatial multi-agent programming model, which has been developed for assessing policy options in the diffusion of innovations and resource use changes. Unlike conventional simulation tools used in agricultural economics, the model class described here applies a multi-agent/cellular automata (CA) approach by using heterogeneous farm-household models and capturing their socia...

BACKGROUND Hypernatraemia is common in critically ill patients and has been shown to be an independent predictor of mortality. Osmotic urea diuresis can cause hypernatraemia due to significant water losses but is often not diagnosed. Free water clearance (FWC) and electrolyte free water clearance (EFWC) were proposed to quantify renal water handling. We aimed to (i) identify patients with hyper...

This entry examines the relationship between property rights and environmental protection. According to the ‘tragedy of the commons’ model, environmental pollution and resource depletion result from the inadequate specification of property rights in environmental goods. Two solutions typically are offered for averting the ‘tragedy’: (1) specify property rights (that is, privatize the commons) o...

OBJECTIVE To characterize the impact of widespread inventory management policies on stock-outs of essential drugs in Zambia's health clinics and develop related recommendations. METHODS Daily clinic storeroom stock levels of artemether-lumefantrine (AL) products in 2009-2010 were captured in 145 facilities through photography and manual transcription of paper forms, then used to determine his...

Let q ≥ 2 and N ≥ 1 be integers. W. Zhang recently proved that for any fixed ε > 0 and q ≤ N ≤ q1/2−ε , ∑ χ 6=χ0 ∣∣∣∣ N ∑ n=1 χ(n) ∣∣∣∣2|L(1, χ)|2 = (1+ o(1))αq q N , where the sum is taken over all nonprincipal characters χ modulo q, L(1, χ) denotes the L-functions corresponding to χ , and αq = qo(1) is some explicit function of q. Here we improve this result and show that the same asymptotic ...