Authors:M. Ryan Haley Abstract: Recent research reports that optimal portfolio selection models often perform worse than equal-weight naive diversification in out-of-sample testing. This paper extends this line of inquiry by comparing the out-of-sample performance of the equal-weight naive strategy to the out-of-sample performance of five alternative naive strategies, each of which derives from a simple heuristic that does not require any optimization. Out-of-sample portfolio performance is assessed by mean, standard deviation, skewness, and Sharpe ratio; k-fold cross validation is used as the out-of-sample testing mechanism. The results indicate that the proposed naive heuristic rules exhibit strong out-of-sample performance, in most cases superior to the equal-weight naive strategy. These findings are consequential for at least two reasons: first, if these simple heuristic-based rules outperform the equal-weight naive strategy, then by transitivity they can outperform the mean–variance- and shortfall-optimal portfolio rules that have been shown in the literature to be inferior to the equal-weight naive rule, which further emphasizes the out-of-sample fragility of “optimal” methods; and second, among naive diversification strategies, some appear more robust in out-of-sample testing than others, hence the proposed methods may be useful when forming mixed portfolio selection models wherein a naive strategy is combined with an optimal strategy to improve performance. PubDate: 2017-07-14 DOI: 10.1007/s10436-017-0301-4

Authors:Dian Zhu; Andrew J. Heunis Abstract: We address a problem of stochastic optimal control motivated by portfolio optimization in mathematical finance, the goal of which is to minimize the expected value of a general quadratic loss function of the wealth at close of trade when there is a specified convex constraint on the portfolio, together with a specified almost-sure lower-bound on intertemporal wealth over the full trading interval. A precursor to the present work, by Heunis (Ann Financ 11:243–282, 2015), addressed the simpler problem of minimizing a general quadratic loss function with a convex portfolio constraint and a stipulated almost-sure lower-bound on the wealth only at close of trade. In the parlance of optimal control the problem that we shall address here exhibits the combination of a control constraint (i.e. the portfolio constraint) together with an almost-sure intertemporal state constraint (on the wealth over the full trading interval). Optimal control problems with this combination of constraints are well known to be quite challenging even in the deterministic case, and of course become still more so when one deals with these same constraints in a stochastic setting. We nevertheless find that an ingenious variational approach of Rockafellar (Conjugate duality and optimization, CBMS-NSF series no. 16, SIAM, 1974), which played a key role in the precursor work noted above, is fully equal to the challenges posed by this problem, and leads naturally to an appropriate vector space of dual variables, together with a dual functional on the space of dual variables, such that the dual problem of maximizing the dual functional is guaranteed to have a solution (or Lagrange multiplier) when the problem constraints satisfy a simple and natural Slater condition. We then establish necessary and sufficient conditions for the optimality of a candidate wealth process in terms of the Lagrange multiplier, and use these conditions to construct an optimal portfolio. PubDate: 2017-07-05 DOI: 10.1007/s10436-017-0300-5

Authors:Kyriakos C. Neanidis; Maria Paola Rana; Keith Blackburn Abstract: In a companion study, Blackburn et al. (Econ Theory Bull, 2017), we have developed a theoretical framework for studying interactions between organized crime and corruption, with the view of examining the combined effects of these phenomena on economic growth. The analysis therein illustrates that organized crime has a negative effect on growth, but that the magnitude of the effect may be either enhanced or mitigated in the presence of corruption. In this paper we tackle the ambiguity produced by the coexistence of the two illicit activities with an empirical investigation using a panel of Italian regions for the period 1983–2009. We find that organized crime distorts growth less when it coexists with corruption and show our results to be robust to different specifications, measures of organized crime, and estimation techniques. PubDate: 2017-06-09 DOI: 10.1007/s10436-017-0299-7

Authors:Liu Gan; Zhaojun Yang Abstract: We consider an irreversible investment, of which the sunk cost is financed by a finite-term debt after entering into an option-for-guarantee swap (OGS) with negotiation. The OGS is a three-party agreement among a lender (bank), an insurer, and a borrower (entrepreneur), where the bank lends at a given interest rate to the entrepreneur and if the borrower defaults on debt, the insurer must pay all the principal and remaining interests to the lender instead of the borrower. In return for the guarantee, the borrower must allocate a perpetual American call option to purchase a fraction (guarantee cost) of his equity at a given strike price. We find that the investment threshold decreases but the exercise threshold of the insurer’s option increases with the borrower’s bargaining power. Both the investment and exercise threshold increase with debt maturity, but there is a U-shaped relation between the guarantee cost and debt maturity. The borrower postpones investment once the funding gap or project risk increases. The swap may overcome the inefficiencies from asset substitution and debt overhang, strongly depending on the debt maturity and borrower’s bargaining power. PubDate: 2017-05-18 DOI: 10.1007/s10436-017-0298-8

Authors:Vlad Stefan Barbu; Guglielmo D’Amico; Riccardo De Blasis Abstract: In this paper we propose further advancements in the Markov chain stock model. First, we provide a formula for the second order moment of the fundamental price process with transversality conditions that avoid the presence of speculative bubbles. Second, we assume that the process of the dividend growth is governed by a finite state discrete time Markov chain and, under this hypothesis, we are able to compute the moments of the price process. We impose assumptions on the dividend growth process that guarantee finiteness of price and risk and the fulfilment of the transversality conditions. Subsequently, we develop non parametric statistical techniques for the inferential analysis of the model. We propose estimators of price, risk and forecasted prices and for each estimator we demonstrate that they are strongly consistent and that properly centralized and normalized they converge in distribution to normal random variables, then we give also the interval estimators. An application that demonstrate the practical implementation of methods and results to real dividend data concludes the paper. PubDate: 2017-04-29 DOI: 10.1007/s10436-017-0297-9

Authors:Wassini Arrassen Abstract: This paper studies the determinants of microfinance institutions’ (MFIs) financial performance (FP: self-sustainability and profitability) and social performance (SP: depth of outreach), and examine the FP/SP tradeoffs they face. Based on a sample of 120 MFIs over the period 2000–2009, we use the random effects method to isolate the effect of fixed-time factors such as loan lending technique, legal status and location (sub-region) on MFIs’ behavior. We find that financial expenses, wages and portfolio quality, mainly influence MFIs’ financial performance whereas social performance is mostly influenced by lending methodology and institutional form, and to a lesser extent by location. The analysis of FP–SP shows that mission drift is a concern primarily for banks, mutual/cooperatives and individual lenders. The results question the trend toward microfinance commercialization since it weakens outreach without improving significantly self-sustainability and profitability. PubDate: 2017-04-11 DOI: 10.1007/s10436-017-0296-x

Authors:Yerkin Kitapbayev; Tim Leung Abstract: We study several optimal stopping problems that arise from trading a mean-reverting price spread over a finite horizon. Modeling the spread by the Ornstein–Uhlenbeck process, we analyze three different trading strategies: (i) the long-short strategy; (ii) the short-long strategy, and (iii) the chooser strategy, i.e. the trader can enter into the spread by taking either long or short position. In each of these cases, we solve an optimal double stopping problem to determine the optimal timing for starting and subsequently closing the position. We utilize the local time-space calculus of Peskir (J Theor Probab 18:499–535, 2005a) and derive the nonlinear integral equations of Volterra-type that uniquely characterize the boundaries associated with the optimal timing decisions in all three problems. These integral equations are used to numerically compute the optimal boundaries. PubDate: 2017-03-25 DOI: 10.1007/s10436-017-0295-y

Authors:Chiara Pederzoli; Costanza Torricelli Abstract: Regulators’ stress tests on banks further stimulated an academic debate over systemic risk measures and their predictive content. Focusing on marked based measures, Acharya et al. (Rev Financ Stud 30(1):2–47, 2017) provide a theoretical background to use marginal expected shortfall (MES) for predicting the stress test results, and verify it on the 2009 Supervisory Capital Assessment Program of the US banking system. The aim of this paper is to further test the goodness of MES as a predictive measure, by analysing it in relation to the results of the 2014 European stress tests exercise conducted by the European Banking Authority. Our results underscore the importance of choosing the appropriate index to capture the systemic distress event. In fact MES based on a global market index does not show association with the stress test results, in contrast to Financial MES, which is based on a financial market index, and has a significant information and predictive power. PubDate: 2017-03-21 DOI: 10.1007/s10436-017-0294-z

Authors:Wai-Hong Ho Abstract: This paper explores the dynamic consequences of variable investment-project size in a global economy consisting of many small open countries that are plagued with domestic credit market frictions. As is customary in the literature, borrowers provide some internal funds, but they also need external funds to implement their investment projects, which are subject to the costly-state-verification problem. Contrary to the literature, the investment-project size increases with the country’s own capital stock. We find that financial market globalization may lead to a process of oscillatory convergence, even in the absence of any exogenous shocks, if the investment-project size is very sensitive to the change in capital stock. PubDate: 2017-02-09 DOI: 10.1007/s10436-017-0293-0

Authors:Ping Wu; Robert J. Elliott Abstract: This paper develops a new approach to obtain the price and risk sensitivities of basket options which have a volatility smile. Using this approach, the Black–Scholes model and the Stochastic Volatility Inspired model have been used to obtain an approximate analytical pricing formula for basket options with a volatility smile. It is found that our approximate formula is quite accurate by comparing it with Monte Carlo simulations. It is also proved the option value of our approach is consistent with the option value generated by Levy’s and Gentle’s approaches for typical ranges of volatility. Further, we give a theoretical proof that the option values from Levy’s and Gentle’s works are the upper bound and the lower bound, respectively, for our option value. The calibration procedure and a practical example are provided. The main advantage of our approach is that it provides accurate and easily implemented basket option prices with volatility smile and hedge parameters and avoids the need to use time-consuming numerical procedures such as Monte Carlo simulation. PubDate: 2017-01-30 DOI: 10.1007/s10436-017-0292-1

Authors:Yuki Shigeta Abstract: We study portfolio selections under mean-variance preference with multiple priors for means and variances. We introduce two types of multiple priors, the priors for means and the priors for variances of risky asset returns. As our framework, in the absence of a risk-free asset, the global minimum-variance portfolio is optimal when the investor is extremely ambiguity averse with respect to means, and the equally weighted portfolio is optimal when the investor is extremely ambiguity averse with respect to variances. PubDate: 2016-12-29 DOI: 10.1007/s10436-016-0291-7

Authors:Shahbaz Sheikh Abstract: This study investigates how the ex-ante threat of termination affects firm performance in innovation measured by number of patents and citations. Empirical results show that the threat of termination is negatively associated with both measures of firm innovation. This relation however is sensitive to industry structure. The negative effect of the threat of termination on innovation is statistically significant only for high-tech firms. For low-tech firms there is no statistically significant relation between the threat of termination and firm innovation. One plausible explanation is that high-tech firms are inherently risky and have higher rates of project failure. Adding the risk of higher threat of termination makes the manager more risk averse and forces her to avoid investing in value increasing innovations. Managers in low-tech firms don’t face such pressures. The policy implication is that high-tech firms should lower threat of termination and increase tolerance for project failure to encourage innovation. PubDate: 2016-12-22 DOI: 10.1007/s10436-016-0290-8

Authors:Hideharu Funahashi; Masaaki Kijima Abstract: This study examines the effect of fractional volatility on option prices. To this end, we develop an approximation method for the pricing of European-style contingent claims when volatility follows a fractional Brownian motion. Through extensive numerical experiments, we confirm that the decrease in the smile amplitude under fractional volatility is much slower than that under the standard stochastic volatility model. We also show that the Hurst index under fractional volatility has a crucial impact on option prices when the maturity is short and speed of mean reversion is slow. On the contrary, the impact of the Hurst index on option prices reduces for long-dated options. PubDate: 2016-12-22 DOI: 10.1007/s10436-016-0289-1

Authors:Marcella Lucchetta Abstract: We develop a simple general equilibrium model in which investment in a risky technology is subject to moral hazard and banks can extract market power rents. We show that more bank competition results in lower economy-wide risk, higher social welfare, lower bank capital ratios, more efficient production plans and Pareto-ranked real allocations. Perfect competition supports a second best allocation and optimal levels of bank risk and capitalization. These results are at variance with those obtained by a large literature that has studied a similar environment in partial equilibrium, they are empirically relevant, and carry significant implications for policy guidance. PubDate: 2016-11-30 DOI: 10.1007/s10436-016-0288-2

Authors:Tomohiro Ota Abstract: This paper studies the intraday payment behaviour between heterogeneous banks as well as optimal intraday pricing schemes. The paper shows the social optimality of payment sequencing, which allows a bank to delay payments until the bank receives payments from the counterparty. The payment sequencing allows a bank with high liquidity cost to ‘recycle’ payment inflow from another bank with lower liqudity cost, reducing the aggregate cost of funding of banks to settle all payments. But we also see that the banks have an incentive to delay payments more than the payment sequencing requires. This underscores the importance of social planner’s role reducing settlement delay, while leaving socially efficient payment sequencing. In this context, we compare two different pricing schemes, a standard throughput guideline and a time-varying intraday tariff, to discuss the optimal incentive mechanisms in payment systems for the ‘socially efficient sequential settlement’. PubDate: 2016-11-29 DOI: 10.1007/s10436-016-0287-3

Authors:Aleksandr G. Alekseev; Mikhail V. Sokolov Abstract: Benchmarking is a universal practice in portfolio management and is well-studied in the optimal portfolio selection literature. This paper derives axiomatic foundations of the relative return, which underlies a benchmark-based evaluation of portfolio performance. We show that the existence of a benchmark naturally arises from a few basic axioms and is tightly linked to the economic theory. Our method relies on the use of both axiomatic and economic approaches to index number theory. We also analyze the problem of optimal portfolio selection under complete uncertainty about a future price system, where the objective function is the relative return. PubDate: 2016-11-22 DOI: 10.1007/s10436-016-0286-4

Authors:Jim Y. Jin; Shinji Kobayashi Abstract: The literature recognizes the qualitative effects of risk aversion on oligopolistic market performance, but less is known about their magnitudes. We quantitatively evaluate these effects in Cournot and Bertrand oligopolies where firms maximize mean-variance utilities under linear demand and costs. The impacts are very similar for the two types of oligopoly, but have opposite signs. The impacts of a firm’s risk aversion on outputs, prices, consumer surplus and social welfare can be expressed via potentially observable variables. Since these impacts resemble the effects of firms’ cost changes, a regulator can reduce or eliminate undesirable effects of risk aversion by changing firms’ costs with appropriate countervailing taxes. PubDate: 2016-11-16 DOI: 10.1007/s10436-016-0285-5

Authors:Dilip B. Madan Abstract: Exponentials of squared returns in Gaussian densities, with their consequently thin tails, are replaced by the absolute return to form Laplacian and exponentially tilted Laplacian densities at unit time. Scaling provides densities at other maturities. Stochastic processes with these marginals are identified. In addition to a specific local volatility model the densities are consistent with the difference of compound exponential processes taken at log time and scaled by the square root of time. The underlying process has a single parameter, the constant variance rate of the process. Delta hedging using Laplacian and Asymmetric Laplacian implied volatilities are developed and compared with Black Merton Scholes implied volatility hedging.The hedging strategies are implemented for stylized businesses represented by dynamic volatility indexes. The Laplacian hedge is seen to be smoother for the skew trade. It also performs better through the financial crisis for the sale of strangles. The Laplacian and Gaussian models are then synthesized as special cases of a model allowing for other powers between unity and the square. Numerous hedging strategies may be run using different powers and biases in the probability of an up move. Adapted strategies that select the best performer on past quarterly data can dominate fixed strategies. Adapted hedging strategies can effectively reduce drawdowns in the marked to market value of businesses trading options. PubDate: 2016-11-09 DOI: 10.1007/s10436-016-0282-8

Abstract: In the classical portfolio optimization problem considered by Merton, the resulting constant proportion investment plan requires a diffusive trading strategy. This means that, within any arbitrarily small time interval, the investor must impractically both buy and sell stocks. We study the problems of a mean-square and a power utility investor for whom the trading strategy is constrained to be smooth, i.e. nondiffusive. This means that over sufficiently small time intervals, the investor is either a seller or a buyer of stocks. The mathematical framework is built around quadratic objectives such that trading activity is punished quadratically. Mean-square utility is quadratic, and power utility is covered by quadratic punishment of distance to Merton’s power utility portfolio. We present semi-explicit solutions and, in a series of numerical illustrations, show the impact of trading constraints on the portfolio decision over the investment horizon. PubDate: 2016-11-05 DOI: 10.1007/s10436-016-0283-7

Authors:Ryoichi Ikeda; Yoske Igarashi Abstract: We present a Merton (J Finance, 1974)-type structural model of credit risk in which the borrower firm refinances its debt, there is cost for bankruptcy, and the creditor has an option to extend the date of maturity of debt if the firm defaults. We show that a solution exists in such a model and in that solution the creditor has incentive to extend maturity to avoid bankruptcy cost. We solve the model numerically and argue that such maturity extension option for the creditor can have substantial impact on the debt and stock values of the firm. PubDate: 2016-10-08 DOI: 10.1007/s10436-016-0281-9