Mean-Variance Spanning

The authors propose a likelihood-ratio test of the hypothesis that the minimum-variance frontier of a set of K assets coincides with the frontier of this set and another set of N assets. They study the relation between this hypothesis, exact arbitrage pricing, and mutual fund separation. The exact distribution of the test statistic is available. The authors test the hypothesis that the frontier spanned by three size-sorted stock portfolios is the same as the frontier spanned by thirty-three size-sorted stock portfolios.     

THE MEAN‐GINI EFFICIENT PORTFOLIO FRONTIER

A main advantage of the mean‐variance (MV) portfolio frontier is its simplicity and ease of derivation. A major shortcoming, however, lies in its familiar restrictions, such as the quadraticity of preferences or the normality of distributions. As a workable alternative to MV, we present the mean‐Gini (MG) efficient portfolio frontier. Using an optimization algorithm, we compute MG and mean‐extended Gini (MEG) efficient frontiers and compare the results with the MV frontier. MEG allows for the explicit introduction of risk aversion in building the efficient frontier. For U.S. classes of assets, MG and MEG efficient portfolios constructed using Ibbotson (2000) monthly returns appear to be more diversified than MV portfolios. When short sales are allowed, distinct investor risk aversions lead to different patterns of portfolio diversification, a result that is less obvious when short sales are foreclosed. Furthermore, we derive analytically the MG efficient portfolio frontier by restricting asset distributions. The MG frontier derivation is identical in structure to that of the MV efficient frontier derivation. The penalty paid for simplifying the search for the MG efficient frontier is the loss of some information about the distribution of assets.     

Efficient frontiers in estate planning

This article explores the nature of the efficient frontier in probabilistic estate planning for 16 different estate plans by considering as random variables ages at death, rates of return on assets, and borrowing rates on debts. The simulation considers two couples, one middle aged, the other elderly. Two 16 × 16 matrices, one for each couple, are used to record and compare the results of every simulation. That comparative data, in conjunction with the coefficient of variation based efficient frontier, contain useful information for couples who, consistent with their levels of risk, desire to maximize the net present value of assets passing to their heirs. The efficient frontier is shown to be a function of three factors: assumptions, ages of the estate owners, and the discount rates of the heirs. Because of the instability shown in the efficient frontier, estate planners and estate owners must carefully examine not only the estate plans which fall on the efficient frontier but also those estate plans which fall just off that frontier.     

Testing for mean-variance spanning: a survey

In this paper, we present a survey on the various approaches that can be used to test whether the mean-variance frontier of a set of assets spans or intersects the frontier of a larger set of assets. We analyze the restrictions on the return distribution that are needed to have mean-variance spanning or intersection. The paper explores the duality between mean-variance frontiers and volatility bounds, analyzes regression-based test procedures for spanning and intersection, and shows how these regression-based tests are related to tests for mean-variance efficiency, performance measurement, optimal portfolio choice and specification error bounds.     

Capital controls,competitive depreciation,and the technological frontier

This paper considers the internal and external welfare effects of international capital controls and real exchange rate undervaluation in a multi-country setting. I present a dynamic open-economy macro model with an endogenously determined rate of interest on internationally traded assets. All countries produce tradable and nontradable goods using technology that converges over time to a global frontier. The model quantifies the welfare effects of the unilateral implementation of capital controls that depreciate the real exchange rate in economies both already at and converging to the technological frontier. For developing economies, I demonstrate that such government interventions may constitute “beggar-thy-neighbor” policies.     

An analysis of portfolio selection with background risk

This paper investigates the impact of background risk on an investor’s portfolio choice in a mean–variance framework, and analyzes the properties of efficient portfolios as well as the investor’s hedging behaviour in the presence of background risk. Our model implies that the efficient portfolio with background risk can be separated into two independent components: the traditional mean–variance efficient portfolio, and a self-financing component constructed to hedge against background risk. Our analysis also shows that the presence of background risk shifts the efficient frontier of financial assets to the right with no changes in its shape. Moreover, both the composition of the hedge portfolio and the location of the efficient frontier are greatly affected by a number of background risk factors, including the proportion of background assets in total wealth and the correlation between background risk and financial risk.     

Positively Weighted Portfolios on the Minimum-Variance Frontier

Duality theory is employed to provide necessary and sufficient conditions for portfolios on the minimum-variance frontier to have positive investment proportions in all assets. These conditions involve the feasibility of portfolios that have non-negative correlation with all assets and positive correlation with at least one. Using these results, several “qualitative” results concerning the signs of investment proportions in efficient portfolios are proved. It is argued that the conditions that ensure all-positive weights in efficient portfolios are intuitively compelling and are not unique to the CAPM. With large numbers of assets, however, the signs of weights in minimum-variance portfolios can be very sensitive to slight departures from these conditions due to, for example, sampling error.     

新会计准则颁布对我国上市公司长期资产减值准备计提影响的实证研究

2006年国家财政部颁布了新的会计准则体系,新准则禁止计提的长期资产减值转回.在"盈余管理工具论"的观点下,人们普遍预期我国上市公司会在06年将原已计提的长期资产减值准备转回.本文对我国上市公司从01年到06所计提的长期资产减值准备进行了分析,并未找到支持这一现点的证据,"盈余管理工具论"在上市公司整体层面上还缺少有说服力的证据.     

Capacity overhang and corporate disinvestment decisions

We use a stochastic frontier model to estimate a firm's capacity overhang. We find that excess capacity is positively related to a drop in new capital expenditures, an accumulation of depleted long-term assets, and outright sales of investment assets. However, the sale of long-term assets (property, plant, and equipment [PP&E]) peaks for intermediate levels of excess capacity and then declines. We attribute this to growth options. We test for evidence of a preference ordering in the firm's choice of responding to excess capacity and find evidence for a pecking order in firm disinvestment, where sales of long-term assets are a measure of last resort.     

The premium of dynamic trading in a discrete-time setting

Chiu and Zhou [Quant. Finance, 2011, 11, 115–123] show that the inclusion of a risk-free asset strictly boosts the Sharpe ratio in a continuous-time setting, which is in sharp contrast to the static single-period case. In this paper, we extend their work to a discrete-time setting. Specifically, we prove that the multi-period mean-variance efficient frontier generated by both risky and risk-free assets is strictly separated from that generated by only risky assets. As a result, we demonstrate that the inclusion of a risk-free asset strictly enhances the best Sharpe ratio of the efficient frontier in a multi-period discrete-time setting. Furthermore, we offer an explicit expression for the enhancement of the best Sharpe ratio, which was referred to as the premium of dynamic trading by Chiu and Zhou [op. cit.], although they do not present a computational formula for it. Our results further show that, in the case with a risk-free asset, if an investor can extract some money from his initial wealth at time 0, the efficient frontier with a risk-free asset can be tangent to that without a risk-free asset. Finally, based on real data from the American market, a numerical example is provided to illustrate the results obtained in this paper; a numerical comparison between the discrete-time case and the continuous-time case is also provided. Our numerical results reveal that the continuous-time model can be considered to be a limit of the discrete-time model.     

Optimal holding period for assets that must be liquidated: A certainty equivalent wealth approach

Consumers often invest with a specific goal in mind and often know with some precision when the investment proceeds will be needed to achieve that goal. Because different investors have different attitudes toward risk and because different asset types exhibit different risk characteristics, there is often confusion as to the appropriate investment asset for a particular investor with a known investment horizon. It is also frequently, unclear as to whether investments should be switched to a less risky asset as time to liquidation becomes short. This paper addresses the issues of initial asset choice and the advisability of switching among assets when the investment goal date is known, employing the methodology of certainty equivalent wealth. In addition to suggesting optimal investment strategies for individuals based upon holding period and degree of risk aversion, it shows that switching investment assets produces suboptimal results.     

Subjective evaluation of delayed risky outcomes for buying and selling positions: the behavioral approach

This paper analyzes time discounting as a function of risk, using reservation prices. Based on experimental data, we compare bidder reservation prices for riskless assets with those for risky assets. The experiments rely on a second price auction with real monetary incentives and real delay in payoffs. We estimate the pure time discount rate for different maturities, considering riskless assets (bonds) and risky assets (delayed lotteries). An innovation in the experimental design allows disentangling pure time from pure risk discounting effects. If subjects bid for assets, we find implied discount rates for risky assets to be uniformly lower than those for riskless assets, across all maturities (the risk moderation effect). However, there is no risk moderation effect if subjects quote ask prices. We argue that delaying a payoff has a stronger effect on the price of bonds than on the price of risky assets since, in the case of bonds, the investor moves from a position of certainty to a position of risk, or uncertainty. Our findings on the risk moderation effect may be used to explain the attractiveness of compensation contracts with options, as commonly used in the financial industry.     

Misintermediation and macroeconomic fluctuations

Individuals plan consumption and production for different point in the future, using interest rates of various maturities as a guide. However, the financial intermediaries individuals work through traditionally do not match the maturity structure of their assets and liabilities. As a result, aggregate production plans and aggregate consumption plans for each period in the future need not coincide. The resulting discrepancy will eventually appear as a recession or boom, involving an unanticipated change in interest rates and production inside the original intertemporal production possibilities frontier. Maturity transformation is therefore not an essential function of financial intermediation, but rather a misfunction, one which we call ‘misintermediation’.     

Can advanced markets help diversify risks in frontier stock markets? Evidence from Gulf Arab stock markets

This study examines global diversification benefits from the perspective of local investors in the frontier markets in the Gulf Cooperation Council using two diversification measures: the correlation index and return dispersion. The findings suggest a strong link between market volatility and both diversification measures in all markets, with the exception of Bahrain, indicating that investors in these frontier markets will face significant challenges achieving desired levels of diversification using domestic stocks only. However, I also find that significant amount of market risk in these countries can be eliminated by supplementing domestic portfolios with positions in advanced markets. Finally, I show that risk minimization strategies using foreign traded assets also lead to favorable risk adjusted returns for investors in these markets, stressing the potential benefits of financial liberalization in developing markets.     

Portfolio selection with mental accounts and delegation

Das et al. (2010) develop an elegant framework where an investor selects portfolios within mental accounts but ends up holding an aggregate portfolio on the mean-variance frontier. This investor directly allocates the wealth in each account among available assets. In practice, however, investors often delegate the task of allocating wealth among assets to portfolio managers who seek to beat certain benchmarks. Accordingly, we extend their framework to the case where the investor allocates the wealth in each account among portfolio managers. Our contribution is threefold. First, we provide an analytical characterization of the existence and composition of the optimal portfolios within accounts and the aggregate portfolio. Second, we present conditions under which such portfolios are not on the mean-variance frontier, and conditions under which they are. Third, we show that the aforementioned analytical characterization is also applicable within the framework of Das et al. and thus improves upon their numerical approach.     

Dispelling fiscal illusions: how much progress have governments made in getting assets and liabilities on balance sheet?

When rights and obligations are not recognized as assets and liabilities on a government's balance sheet, the government's deficit can be reduced by selling unrecognized assets or incurring unrecognized liabilities. This paper examines how much has been done in 28 advanced economies since 2003 to recognize assets and liabilities and thus dispel the fiscal illusions that such transactions create. Good progress has been made in the recognition of some assets and liabilities, such as shares owned and accounts payable, but much less in others, such as pensions for civil servants.     

Optimal Gradual Annuitization: Quantifying the Costs of Switching to Annuities

We compute the optimal dynamic annuitization and asset allocation policy for a retiree with Epstein–Zin preferences, uncertain investment horizon, potential bequest motives, and pre‐existing pension income. In our setting the retiree can decide each year how much he consumes and how much he invests in stocks, bonds, and life annuities, while the prior literature mostly considered restricted so‐called deterministic or stochastic switching strategies. We show that postponing the annuity purchase is no longer optimal in the gradual annuitization (GA) case since investors are able to attain the optimal mix between liquid assets (stocks and bonds) and illiquid life annuities each year. In order to assess potential utility losses, we benchmark various restricted annuitization strategies against the unrestricted GA strategy.     

Macroeconomic influences on optimal asset allocation

We develop a tactical asset allocation strategy that incorporates the effects of macroeconomic variables. The joint distribution of financial asset returns and the macroeconomic variables is modelled using a VAR with a multivariate GARCH (M-GARCH) error structure. As a result, the portfolio frontier is time varying and subject to contagion from the macroeconomic variable. Optimal asset allocation requires that this be taken into account. We illustrate how to do this using three risky UK assets and inflation as a macroeconomic factor. Taking account of inflation generates portfolio frontiers that lie closer to the origin and offers investors superior risk-return combinations.     

Accruals: An overview

The paper provides a broad discussion of the topic "accruals". Though much of what is said is familiar from the literature on accruals, the paper tries to develop concepts and show how theses forge tight links across a variety of themes. The starting point of the analysis concerns the construct of an accrual.The case is made that it should rest solely on consecutive balance sheets and the splitting of assets/liabilities into(i) cash and approximate cash,assets/liabilities and(ii) all other kinds of assets/liabilities. Given this divide of assets/liabilities one can measure the components in the foundation equation: cash earnings + net accrual = comprehensive earnings. The paper then proceeds to discuss how the net accrual relates to growth in a firm's operating activities and the extent to which it can be informative or misleading.This topic in turn integrates with the issue of a firm's quality of earnings and the role of accounting conservatism. Among the remaining topics, the paper discusses how one conceptualizes diagnostics to assess whether or not a period's accrual is likely to be biased upwards or downwards. It gives rise to a consideration of how one constructs accruals that may be more informative than GAAP accruals and the role of value-relevance studies to assess the information content of accrual constructs. The paper ends with a list of suggestions how future research may be modified in light of the discussions in this paper.