A capital adequacy buffer model

We develop a new capital adequacy buffer model (CABM) that is sensitive to dynamic economic circumstances. The model, which measures additional bank capital required to compensate for fluctuating credit risk, is a novel combination of the Merton structural model, which measures distance to default and the timeless capital asset pricing model (CAPM), which measures additional returns to compensate for additional share price risk. We apply the model to a portfolio of mid-cap loan assets over a 10-year period that includes pre-GFC (global financial crisis), GFC and post-GFC. An analysis of actual defaults over this period shows the model to be far more accurate in determining the capital adequacy levels needed to counter credit risk than an unresponsive ratings model such as the Basel standardized approach.     

ON THE ROLE OF THE GROWTH OPTIMAL PORTFOLIO IN FINANCE

The paper discusses various roles that the growth optimal portfolio (GOP) plays in finance. For the case of a continuous market we show how the GOP can be interpreted as a fundamental building block in financial market modeling, portfolio optimisation, contingent claim pricing and risk measurement. On the basis of a portfolio selection theorem, optimal portfolios are derived. These allocate funds into the GOP and the savings account. A risk aversion coefficient is introduced, controlling the amount invested in the savings account, which allows to characterize portfolio strategies that maximise expected utilities. Natural conditions are formulated under which the GOP appears as the market portfolio. A derivation of the intertemporal capital asset pricing model is given without relying on Markovianity, equilibrium arguments or utility functions. Fair contingent claim pricing, with the GOP as numeraire portfolio, is shown to generalise risk neutral and actuarial pricing. Finally, the GOP is described in various ways as the best performing portfolio.     

New approach to estimating the cost of common equity capital for public utilities

The regulatory process for setting public utilities’ allowed rate of return on common equity has generally used the Gordon DCF, CAPM and Risk Premium specifications to estimate the cost of common equity. Despite the widely known problems with these models, there has been little movement to adopt more recently developed asset pricing models to provide additional evidence for estimating the cost of capital. This paper presents, validates empirically and applies a general yet simple consumption-based asset pricing specification to model the risk-return relationship for stocks and estimate the cost of common equity for public utilities. The model is not necessarily superior to other models in its practical results, yet these results do indicate that it should be used to provide additional estimates of the cost of common equity. Additionally, the model raises doubts as to whether assets such as utility stocks are a consumption (business cycle) hedge.     

A possibilistic portfolio adjusting model with new added assets

In order to fit changes in financial markets, portfolio managers often need to revise an existing portfolio. This article analyzes the portfolio adjusting problem with new added assets. We propose a possibilistic portfolio adjusting model with transaction costs and bounded constraints on holdings of assets, which can be transformed into a linear programming problem. Both the lower bounds on holdings and the total investment constraints influence the optimal portfolio adjusting strategies. Furthermore, a numerical example of a portfolio adjusting problem is given to illustrate our proposed effective approaches. The numerical results show the case that investors do not need to invest total capital and to hold all assets in the portfolio for some required return levels.     

An evolutionary approach to the examination of capital market efficiency

The paper investigates capital market efficiency on basis of an evolutionary model of asset pricing. Participants of capital markets are considered as organizations in the sense of Nelson and Winter (1982). Behavior of these organizations is described by routines. Routines are regular and predictable behavioral patterns, which determine how individuals gather information, form expectations, and order assets. The participants change their behavior by innovating new routines or by imitating routines of other participants.     

Risk index based models for portfolio adjusting problem with returns subject to experts' evaluations

This paper discusses a portfolio adjusting problem with additional risk assets and a riskless asset in the situation where security returns are given by experts' evaluations rather than historical data. Uncertain variables are employed to describe the security returns. Using expected value and risk index as measurements of portfolio return and risk respectively, we propose two portfolio optimization models for an existing portfolio in two cases, taking minimum transaction lot, transaction cost, and lower and upper bound constraints into account. In one case the riskless asset can be both borrowed and lent freely, and in another case the riskless asset can only be lent and the borrowing of riskless asset is not allowed. The adjusting models are converted into their crisp equivalents, enabling the users to solve them with currently available programming solvers. For the sake of illustration, numerical examples in two cases are also provided. The results show that under the same predetermined maximum tolerable risk level the expected return of the optimal portfolio is smaller when the riskless asset can only be lent than when the riskless asset can be both borrowed and lent freely.     

Market structure and the cost of capital

We contribute to the finance literature in two main ways. First, we present a theoretical capital asset pricing model (CAPM) to price assets in different market structures. Second, we use our model to analyze whether when markets are partially segmented using the local or the global CAPM yields significant errors in the estimation of the cost of capital for a sample of firms from developed and emerging countries.     

Nature,roads or hospitals? An empirical evaluation of ‘sustainable development preferences’

While a key proposition is that a sustainable path is one where wealth does not decline, whether losses in natural capital can be compensated in wellbeing terms by more produced, social or natural capital remains an area of controversy. In this paper, we seek to better understand preferences for different combinations of assets that comprise (part of) the asset portfolio of a nation. In a study of coastal and marine natural assets, we test for the existence of weak or strong sustainability preferences using different compensation options (respectively produced capital and natural capital) offered to a sample of the public in Spain in the case of possible future oil spills. As a further element of this test, we provide an empirical reflection on Aldred (2002, 2006) and Turner (2007) who speculate that individuals may not view money as compensating for certain environmental losses whereas investments in social assets may offer a more acceptable compensation option. Our results do appear to circumscribe in some way the acceptability of investing in produced capital and reveal a tendency towards a preference for social capital compensation. Nevertheless, the size of the oil spill and the environmental beliefs of respondents also influence choices over the natural capital compensation option.     

Portfolio choice, attention allocation, and price comovement

This paper models the attention allocation of portfolio investors. Investors choose the composition of their information subject to an information flow constraint. Given their expected investment strategy in the next period, which is to hold a diversified portfolio, in equilibrium investors choose to observe one linear combination of asset payoffs as a private signal. When investors use this private signal to update information about two assets, changes in one asset affect both asset prices and may lead to asset price comovement. The model also has implications for the transmission of volatility shocks between two assets.     

On trees and logs

In this paper we contrast the main workhorse model in asset pricing theory, the Lucas (1978) tree model (LT-Model), to a benchmark model in financial equilibrium theory, the real assets model (RA-Model). It is commonly believed that the two models entail similar conclusions since the LT-Model is a special case of the RA-Model. But this is simply wrong: implications of these models can be strikingly at odds. Indeed, under the widely used log-linear specification of households’ preferences, we show that for a large set of initial endowments the LT-Model—even with potentially complete financial markets—admits only peculiar financial equilibria in which the stock market is completely degenerate, in that all stocks offer the same investment opportunity—and yet, allocation is Pareto optimal. We investigate why the LT-Model is so much at variance with the RA-Model, and uncover new results on uniqueness of financial equilibria and introduction of portfolio constraints obtaining in the LT-Model, but not in the RA-Model.     

Endogenous current account balances in a world CGE model with international financial assets

This paper presents an applied computable general equilibrium world model with financial assets and endogenous current account, and capital and financial account balances. The capital and financial account equilibrium conditions, rather than exogenous rules, constrain the current account balance. International capital flows which balance the current account are constrained by supply-and-demand equilibrium conditions on the market for international debt securities, under portfolio managers' optimizing behavior. The asset–liability structure of the financial portfolio is endogenous, and it is possible for a country-agent to have negative net financial assets. In simulations, the interaction of portfolio choices with trade supply and demand behavior leads to endogenous sign reversals in some current account balances, and it results in a different allocation of investment among regions, compared to a model with exogenously determined current account balances. In the reference scenario, this allocation generates growth that is about the same globally, but differently distributed between regions.     

Uniform testing and portfolio strategies for single and multifactor asset pricing models in the Pacific Basin markets

We test and implement portfolio strategies for three major asset pricing models, under uniform diagnostic measures using the PACAP data set containing all current listing and de-listing of firms for the local stock exchange in several Pacific Basin countries. Compared to the often used MSCI database that include only a subset of the (large) firms in the local markets, the more complete coverage of our database allows for more robust testing of current multifactor asset pricing models since the possible effects of additional factors such as size and book to market may not show up correctly using less comprehensive data sets. Our data set also provides a natural packet of nonUS data for addressing the issue of whether the results of recent asset pricing research are sample specific. Our overall results provide multi-country (sample nonspecific) support for the additional asset pricing risk factors of the Fama-French three-factor model but not for the momentum factor of the Carhart model. We additionally find that the size risk factor is more prominent than value risk factor in the Pacific Basin markets. Finally, we find strong evidence that portfolio strategies implemented to capture value and size effects are profitable in the Pacific Basin stock markets.     

考虑基准资产的动态投资组合选取

职业基金经理的目标经常是希望自己的投资组合以稳定的表现能够超越所某一基准资产或组合。因此本文给出一个考虑基准资产的动态均值——方差投资组合选取模型。假设状态之间的转移遵循马氏过程,给定状态转移矩阵,可以得到对风险资产最优投入的解析表达式。此表达式表明对风险资产的投入由三项构成,前两项是不考虑基准资产时对风险资产的投入,最后一项与基准资产有关;在基准资产上的权重由基准资产收益的大小来决定,与积极投资组合管理者的风险厌恶程度无关;随着风险厌恶程度的增加,管理者会减少在风险资产上的投入。数值分析显示考虑基准资产的投资组合是一个积极的投资组合。     

A unified beta pricing theory

This paper derives Ross's mutual fund separation theory and a new, equilibrium version of Ross's arbitrage pricing theory as special cases of a general theory. The paper also reveals that the two theories are identical in their predictions of asset prices and portfolio returns. The capital asset pricing model (a restricted case of the mutual fund separation theory) receives special treatment.     

Empirical tests on the asset pricing model with liquidity risk: An unobserved components approach

The aim of this paper is to test empirically the conditional liquidity-adjusted capital asset pricing model (L-CAPM) developed by Acharya and Pedersen (2005). Accordingly, we propose to estimate the L-CAPM using unobserved components methodology, which allows us to take into account the main stylized facts characterizing liquidity. Based on a sample of firms listed on the NASDAQ, our empirical analysis reveals several findings. Firstly, we show that liquidity is time-varying and exhibits strong seasonality. Secondly, we highlight the impact of the liquidity level premium on asset prices. Thirdly, we show that the most important liquidity risk is related to the covariance between portfolio illiquidity and market returns. Fourthly, we observe a negative relationship between portfolio returns and market illiquidity. Fifthly, we find that liquidity risk and illiquidity level are not always positively correlated.     

Aggregation of heterogenous beliefs,asset pricing,and risk sharing in complete financial markets

Given a competitive equilibrium in complete asset markets, we propose a method that aggregates heterogeneous individual beliefs into a single “market probability,” which, if commonly shared by investors, generates the same marginal valuation of assets by the market as well as by each individual investor. As a result of the aggregation process, the market portfolio may have to be scalarly adjusted, upward or downward, a reflection of an aggregation bias due to the diversity of beliefs. From a dual viewpoint, the standard construction of an expected utility-maximizing aggregate investor designed to represent the economy in equilibrium, is shown to be also valid in the case of heterogeneous beliefs, modulo the above scalar adjustment of the market portfolio, thereby generating an Adjusted version of the Consumption based Capital Asset Pricing Model (ACCAPM). We analyze how the allocation of aggregate and individual risks relates to deviations of individual beliefs from the aggregate market probability. Finally, we identify the channels through which the distribution of beliefs and other microeconomic characteristics (incomes, attitudes toward risk) across investors impact the pricing of risky assets an may contribute to explaining the equity premium puzzle.     

International asset market, nonconvergence, and endogenous fluctuations

We develop an overlapping generations model with re-tradeable paper assets and capital accumulation to analyze the interaction between the real economy and an international asset market. The world consists of two homogeneous countries, which differ only in their initial levels of capital. Consumers who live for two periods transfer wealth over time and across countries by holding international mutual funds which pay stochastic dividends. The optimal portfolio decisions of consumers do not necessarily induce convergence of incomes between the two countries. Moreover, interaction through the asset market induces endogenous fluctuation of capital flows between the rich and the poor country.     

Single Beta Models and Currency Futures Prices

The conditional capital asset pricing model is applied to foreign currency futures prices, covariance risk being measured relative to excess returns from a broadly diversified international portfolio of equities. Positive time-varying risk premia are found in all five currencies tested when the difference between the US and the average foreign interest rates is used as an instrumental variable for the expected excess return from the common stock portfolio.     

流动性、生命周期与投资组合相异性——中国投资者行为调查实证分析

本文采用Probit和Tobit模型对中国居民的股票市场参与和投资组合的影响因素进行了分析,主要有以下的实证发现:首先,不流动性资产特别是房地产的投资显著影响了投资者的股票市场参与和投资组合,而且影响以“替代”效应或者说“挤出”效应为主。其次,投资者在进行投资组合时极少利用股票市场对其未来现金流所承担的风险进行对冲,也就是说,中国居民投资的“生命周期效应”不明显;第三,中国居民投资的“财富效应”非常显著。财富的增加既增加了居民参与股票市场的概率,也增加了居民参与股票市场的深度。     

Financial market integration: Theory and empirical results

In this article, we introduce a new theoretical international asset pricing model which accounts for partial financial market segmentation. We show that if some investors do not hold all international assets because of implicit and/or explicit segmentation factors, the world market portfolio is not efficient and the classic ICAPM must be augmented by a new factor reflecting the local risk undiversifiable internationally. We test this model empirically for a sample of emerging markets. Our findings show that the degree of market integration is time-varying and that the premium associated with the domestic risk factors is the most important component of the total risk premium. However, our results also show that most of the emerging markets we study have become more integrated in the end of our sample period as a result of liberalization and reforms.