金融创新、金融风险与金融稳定的理论分析

金融创新、金融风险和金融稳定的关系是一个具有现实意义的问题,金融创新是金融领域各种要素的重新优化组合和金融资源的重新配置。从微观层面看,金融创新对金融稳定的促进作用体现在金融风险规避、金融效率提高和金融市场发展。从宏观层面看,金融创新有助于货币融通、金融体系稳定和金融发展安全等。而另一方面,金融创新可能带来金融脆弱性、危机传染性和系统性风险,并给金融监管带来巨大挑战,对金融安全产生负面冲击。     

Adding and subtracting Black-Scholes: A new approach to approximating derivative prices in continuous-time models

We develop a new approach to approximating asset prices in the context of continuous-time models. For any pricing model that lacks a closed-form solution, we provide a closed-form approximate solution, which relies on the expansion of the intractable model around an “auxiliary” one. We derive an expression for the difference between the true (but unknown) price and the auxiliary one, which we approximate in closed-form, and use to create increasingly improved refinements to the initial mispricing induced by the auxiliary model. The approach is intuitive, simple to implement, and leads to fast and extremely accurate approximations. We illustrate this method in a variety of contexts including option pricing with stochastic volatility, computation of Greeks, and the term structure of interest rates.     

Modeling approaches for the design of resilient supply networks under disruptions

This paper studies various modeling approaches to design resilient supply networks (SN) for the location-transportation problem under uncertainty. The future environment of the SN is shaped by random demands, and by disruptions perturbing depots capacity and ship-to-point demand processes. The paper proposes several stochastic programming models incorporating alternative resilience seeking formulations. A generic approach to model SN disruptions, and to elaborate and evaluate SN designs is also proposed. Experiments are made to compare the SN design models formulated, and recommendations are drawn on the approach to use to design effective and robust supply networks.     

Impact of quality on estimations of hotel efficiency

This paper provides empirical evidence on the impact of output quality on hotel efficiency. It demonstrates how ignoring quality can lead to erroneous efficiency estimates. The study uses stochastic frontier methodology and the model proposed by Battese and Coelli (1995) to estimate the efficiency of 838 hotels in Spain in the period 2009–2013. The key advantage of this methodology is its ability to estimate efficiency and identify factors that explain differences in efficiency in a single-stage sampling procedure. Estimates of cost efficiency, which only include the costs of higher quality, are compared to those of profit efficiency, which not only consider costs but also the revenues generated by higher quality. Results show that quality has a negative impact on cost efficiency and a positive one on profit efficiency. Thus, hotel management should implement strategies that increase the value of their services as a way to achieve sustainable competitive advantages.     

Asset prices in affine real business cycle models

I describe a tractable way to study macroeconomic quantities and asset prices in a large class of dynamic stochastic general equilibrium models. The proposed approximate solution is analytical, log-linear, and adjusted for risk. Therefore, it is well suited to investigate economic mechanisms, describe the time series properties or estimate the model, and deal with stochastic volatility. I explain the pitfalls encountered by previous attempts to use simple approximation techniques, in particular with models featuring recursive preferences. Finally, I show the theoretical relationship between my solution and higher-order perturbation methods.     

A many-to-many ‘rural hospital theorem’

We show that the full version of the so-called ‘rural hospital theorem’ generalizes to many-to-many matching problems where agents on both sides of the problem have substitutable and weakly separable preferences. We reinforce our result by showing that when agents’ preferences satisfy substitutability, the domain of weakly separable preferences is also maximal for the rural hospital theorem to hold.     

International borrowing without commitment and informational lags: Choice under uncertainty

A series of recent studies in economic growth theory have considered a class of models of international borrowing where, in the absence of a perfect investment commitment, the borrowing constraint depends on the historical performances of the country. Thus, a better level of past economic activity gives a higher reputation, thereby increasing the possibility of accessing the international credit market. This note considers this problem in a stochastic setting based on the volatility of the internal net capital. We study how the optimal consumption level and the maximal expected welfare depend on the combined influence of the trajectory of past economic variables and the volatile environment. In particular, we show how the strength of the history effect and the relative weight of the historical performance depend on the degree of risk.     

Measuring systemic risk with regime switching in tails

This paper motivates the importance of modeling nonlinearities in measuring systemic risk. I capitalize this motivation by generalizing the CoVaR approach proposed by Adrian and Brunnermeier (2016) to allow it switching between a high and a normal risk regime filtered from data.. Considering the U.S. large bank holding companies (BHCs), this paper shows that modeling regime changes in tails is capable of capturing both amplification and mean-reversion effects of an adverse shock to a bank's balance sheet on the banking system. Using the Kolmogorov–Smirnov test statistics with and without bootstrapping, I perform the significance test to identify systemically important financial institutions (SIFIs), and the stochastic dominance test to rank the identified SIFIs. The stochastic dominance test raises the concern that the CoVaR measure underestimates systemic risk contributions for SIFIs but overestimates for non-SIFIs. Finally, applying the BHCs' characteristics and housing market price to forecast the regime-switching systemic risk out-of-sample, I obtain from 4- and 8-quarter-ahead horizons a desirable countercyclical, forward-looking measure of systemic risk.     

国际金融危机对广西经济金融的影响分析

源自美国的次贷危机已经演变为波及全球的国际金融危机,国际金融危机对广西经济金融的影响不同程度的存在,进出口形势严峻,投资意愿不足,消费可持续性有待观察,工业和农业面临诸多压力,银行业、证券业和保险业的风险也不同程度地放大,国际金融危机对广西经济金融的影响不容忽视。     

Optimal portfolios and Heston's stochastic volatility model: an explicit solution for power utility

Given an investor maximizing utility from terminal wealth with respect to a power utility function, we present a verification result for portfolio problems with stochastic volatility. Applying this result, we solve the portfolio problem for Heston's stochastic volatility model. We find that only under a specific condition on the model parameters does the problem possess a unique solution leading to a partial equilibrium. Finally, it is demonstrated that the results critically hinge upon the specification of the market price of risk. We conclude that, in applications, one has to be very careful when exogenously specifying the form of the market price of risk.