Few proposed types of derivative securities have attracted as much attention and interest as option contracts on volatility. Grunbichler and Longstaff (1996) is the only study that proposes a model to value options written on a volatility index. Their model, which is based on modeling volatility as a GARCH process, does not take into account the switching regime and asymmetry properties of volatility. We show that the Grunbichler and Longstaff (1996) model underprices a three-month option by about 10%. A Switching Regime Asymmetric GARCH is used to model the generating process of security returns. The comparison between the switching regime model and the traditional uni-regime model among GARCH, EGARCH, and GJR-GARCH demonstrates that a switching regime EGARCH model fits the data best. Next, the values of European call options written on a volatility index are computed using Monte Carlo integration. When comparing the values of the option based on the Switching Regime Asymmetric GARCH model and the traditional

This article examines local entrepreneurialism and the governance logic of local states under China's cadre assessment mechanism. By highlighting the ubiquitous performance competition and promotion pressure faced by local officials, it argues that building performance and seeking promotion during the tenure are the internal impulses for Chinese local states and their leaders to pursue entrepreneurialism. In China's politico-institutional soil, therefore, entrepreneurial actions are not necessarily designed to enhance local attractiveness and competitiveness in the global market, but serve as a means for local officials to accumulate political capital and pursue career advancement. Lanzhou's urban renewal is used as a case to illustrate how city leaders advance individual careers through entrepreneurialism. By interpreting the impact of cadre assessment mechanism on local governance, the study sheds light on the ubiquitous inter-scalar politics in China. It also enriches our understanding of China's urban entrepreneurialism by revealing the political intent behind local governance actions.

No abstract

Microporous layer (MPL) is a vital component for proton-exchange membrane fuel cells (PEMFCs) to improve the cell performance. However, the conventional preparation of MPL, involving the mixing of carbon black with hydrophobic agent polytetrafluoroethylene (PTFE), followed by high-temperature annealing, is often complicated and costly. Herein, we present a facile and low-cost method to fabricate the MPL by functionalization of carbon black via covalent bonding with hydrophobic agent. Upon chemical grafting with fluoroalkylsilane (FAS-17), the water contact angle of carbon black is increased from 66.4 to 150.4°, resulting in superhydrophobicity. The MPL prepared with the resultant superhydrophobic carbon endows the PEMFC with enhanced gas and water permeability and hereby improved electrochemical performance over traditional MPL, and a maximum power density of 1211 mW cm −2 for the PEMFC can be obtained. This work offers a feasible strategy to construct an efficient MPL for the PEMFC via a chemical grafting approach.

No abstract