Functional Itô calculus†

We extend some results of the Itô calculus to functionals of the current path of a process to reflect the fact that often the impact of randomness is cumulative and depends on the history of the process, not merely on its current value. We express the differential of the functional in terms of adequately defined partial derivatives to obtain an Itô formula. We develop an extension of the Feynman-Kac formula to the functional case and an explicit expression of the integrand in the Martingale Representation Theorem. We establish that under certain conditions, even path dependent options prices satisfy a partial differential equation in a local sense. We exploit this fact to find an expression of the price difference between two models and compute variational derivatives with respect to the volatility surface.     

The role of speculation in international futures markets on commodity prices

The role of futures contracts on spot prices has been one of the key focus areas of research since the recent surge in commodity prices and increase in the volatility of commodity returns. However, no consensus arises from this literature, and hence it is difficult to link the use of futures contracts in agricultural commodities by non-hedgers and the growing food insecurity within developing countries. The purpose of this paper is to highlight causal relationships from futures contracts to spot prices of underlying assets, namely agricultural commodities. As research that focus on exchange-traded funds do not provide any clear conclusions, we focus on the imbalance between short- and long-open positions, this imbalance being caused by the exchange traded funds’ participation in futures markets. In this paper, we estimate relationships between financial variables including indicators for speculation in futures markets and the returns of cocoa, corn, soybean, wheat, coffee, rice, and sugar on a weekly basis from 1998 to 2013. Significant results lead to Granger-causality tests that in turn validate the hypothesis of a positive impact of speculation in futures markets to returns on the underlying commodities.     

Freeing Greece from capital controls: Were the restrictions enforced in time?

Recent developments in Greece have caused for the implementation of banking capital controls on the outflow of funds, a policy decision not uncommon, especially in emerging markets. However, the issues of the Greek economy, which seem to stem from the public sector but have been passed on to the banking sector, pose a unique challenge to researchers. In this paper, we employ VBanking, an object-oriented model for banking simulations to examine whether capital controls in Greece were enforced at the appropriate time. Additionally, we propose that the banking sector will not purge this regulation soon. Finally, we demonstrate the destructive effects of capital controls both on the financial system and on the real economy. We present the empirical results of our work, which suggest that the Greek authorities’ response to the deterioration of the banking sector was lagged.     

Credit market frictions and political failure

We study how an excessively favorable regulatory environment for banks could arise even with a perfectly competitive credit market in a median voter world. In our occupational choice model with heterogeneous wealth endowments, market failure due to unobservability of entrepreneurial talent endogenously creates a misalignment between surplus maximizing reforms and reforms that are preferred by the median voter, who is a worker. This is in contrast to the world without market failure where the electorate unanimously vote in favor of surplus maximizing institutional reforms. This paper illustrates how market failure could lead to political failure even in the benchmark political system that is free from capture by interest groups.     

Flight-to-quality and correlation between currency and stock returns

We document that capital flows in and out of emerging or developed markets are sensitive to global equity market conditions. Capital tends to move out of emerging into developed countries in global down markets, leading to depreciation (appreciation) of emerging (developed) currencies. This generates a positive (negative) correlation between currency and equity in emerging (developed) markets which is amplified by the magnitude of the capital movement. We also verify that hedging currency risks may undo the natural hedge and increase the total return volatility under negative correlation.     

金融发展、资产泡沫与实体经济: 一个文献综述

近年来的金融危机和不同国家的发展路径促使经济学家们反思资产泡沫与实体经济之间的关系。过去几年主流经济学中开始涌现出一些富有洞见的相关理论和实证文献。本文通过一条逻辑主线对基于这些文献的进展进行了系统评述。资产泡沫产生于金融市场的不完全性,它既影响实体经济的效率和增长,也影响实体经济的波动。其中,金融发展程度(金融市场的完全性)扮演了重要的角色。金融发展程度会影响到资产泡沫的产生;而资产泡沫既可以缓解经济中的扭曲,也可以加剧经济中的扭曲,使得经济增长偏离黄金律。制度质量则会强化金融发展程度的影响。金融发展程度与制度质量在开放经济的情况下,还会影响到资本在国际间的流向和结构,从而对实体经济的增长和波动产生更复杂的影响。本文中所综述的理论洞见对于中国这类金融市场欠发达、正面临金融自由化与结构转型的新兴市场经济体尤其具有重要的政策含义。本文最后讨论了中国金融改革和金融发展中需要注意的一些问题。     

Net Equity and Debt Flows to Emerging Market and Developing Economies in the Post-Crisis Era

We investigate the determinants of net equity and debt flows into 60 emerging and developing countries during 1986–2012, with a special focus on the period following the onset of the global financial crisis (GFC). Our results controlling for endogeneity show that net equity flows to emerging markets were mostly influenced by global risk factors, while net debt flows were affected by country-specific factors. We further distinguish the factors that were more pronounced in determining net portfolio flows to emerging markets since the GFC. The US real interest rate had significant spillover effects on net equity flows after the GFC. An increase in country’s domestic credit attracted net debt inflows before the GFC, while it was associated with net equity outflows after the GFC. We also find that capital controls moderated net debt flows since the GFC.     

离散选择模型的基本原理及其发展演进评介

离散选择模型的研究真正兴起于19世纪50年代末，属于微观计量经济学的范畴。该模型能够对个体和家庭行为进行经验性的统计分析，因而在经济学和其他社会科学中得到广泛的应用。本文从离散选择模型的基本性质及效用最大化的理论背景出发，指出logit模型虽然使用的是最早并且最为广泛的离散选择模型，但是其存在着三大局限性：不能表示随机口味的变化、暗含成比例的替代形式和不能处理不可观测因素在不同期间相关的情形。GEV（含嵌套logit）、probit和混合logit模型等其他的离散选择模型，很大程度上都是为了避免这些限制而产生并发展起来的。     

国企改制对中国产权市场的影响

本文从国有企业改制的角度出发,联系我国国企改制和国际公有产权私有化的具体情况,对国有企业产权转让的特殊性进行分析,论述了国企改制对我国产权市场的影响,并提出了改善的对策和建议。