Designing social security - a portfolio choice approach

Public social security systems may provide diversification of risks to individuals’ life-time income. Capturing that a pay-as-you-go system (paygo) may be considered as a “quasi-asset”, we study the optimal size of the paygo system as well as the optimal split between funded and unfunded pension saving by means of a theoretical portfolio choice framework. A low-yielding paygo system can benefit individuals if it contributes to hedge other risks to their lifetime resources. Numerical calculations indicate that optimal social security systems should be at least partly paygo financed in many economies. The optimal magnitude of the paygo system depends on the specified risk concept as well as the stochastic properties of stock market returns and implicit paygo-returns.     

Time to default in the UK mortgage market

This paper employs duration analysis to investigate the timing of default in the UK mortgage market. Our analysis is performed on an ex ante basis, in that our explanatory variables are available to mortgage lenders when the loan is first made. We estimate both standard Weibull distributions and generalizations of the Weibull that permit non-monotonic hazard functions. The models fit the data well, suggesting that we have captured the major sources of variation in duration. We find that ‘cash flow’ variables, such as salary and interest rate paid, play the largest role. Surprisingly, loan-to-value ratios are either insignificant or influence default times in a counter-intuitive direction.     

Short-memory equilibrium in stochastic overlapping generations economies

In stochastic OLG exchange economies, we show that short-memory equilibria—the natural extension from deterministic economies of steady states, low-order cycles, or finite state-space stationary sunspots equilibria—fail to exist generically in utilities. As a result, even with independent and identically distributed exogenous shocks there is serial correlation in endogenous economic variables in equilibrium. This arises even if utilities are time-separable, some goods inferior, and there are no technological lags. Hence, the origins of economic fluctuations can be traced only to the demographic structure of a heterogeneous agent, multiple-good economy.     

Representative consumer's risk aversion and efficient risk-sharing rules

We study the representative consumer's risk attitude and efficient risk-sharing rules in a single-period, single-good economy in which consumers have homogeneous probabilistic beliefs but heterogeneous risk attitudes. We prove that if all consumers have convex absolute risk tolerance, so must the representative consumer. We also identify a relationship between the curvature of an individual consumer's individual risk sharing rule and his absolute cautiousness, the first derivative of absolute risk-tolerance. Furthermore, we discuss some consequences of these results and refinements of these results for the class of HARA utility functions.     

BANK INTEREST MARGINS AND BUSINESS START-UP COLLATERAL: TESTING FOR CONVEXITY

The paper investigates the relationship between bank interest rate margins and collateral for loans issued to new ventures. The analysis finds a convex U‐shaped relationship. The results indicate that while provision of collateral initially reduces bank exposure to risk (through security, more optimal levels of capital and lower moral hazard among entrepreneurs) that beyond a point, the positive risk‐wealth association gives rise to greater risk taking propensity among entrepreneurs and ultimately higher interest rates. This indicates that a lender's pricing policy may even somewhat help to level the competitive playing field between ventures launched by higher and moderately wealthy entrepreneurs.     

Herding in delegated portfolio management: When is comparative performance information desirable?

We address the issue of investors’ asset allocation decisions when portfolio management is delegated to an agent. Contrary to predictions from traditional financial theory, it is shown that investors may not induce their manager to allocate funds to the asset with the highest return. Instead they may herd in their asset allocation decision and induce trade in a particular asset, because another manager is trading in it and despite the presence of a more profitable alternative. Doing so allows investors to write an efficiency-improving relative-performance contract. On the other hand, herding leads investors to design wage contracts strategically, resulting in more aggressive and thus less profitable trade in equilibrium. We show that herding occurs, when the cost of information is high, information precision is low and when managers are sufficiently risk averse. Moreover, when investors can decide whether or not to disclose information about their manager's performance, they will not do so.     

Returns of Small Growth Stocks: An Empirical Analysis

I investigate the mean reversion tendency of small growth stocks. Using a carefully articulated research design employing established and empirically tested principles, my findings should support or refute the anecdotal evidence that small growth stocks make superior investments. The primary motivation for the study springs from the documented differential preference among investors for value and growth stocks. Despite evidence that value stocks tend to outperform growth stocks, investors retain strong interest in growth stocks. Yet in examining the performance of Business Week’s (BW), smaller capitalization companies (called “Hot Growth Companies”) with respect to the overall financial market, Bauman et al. [2002] found positive excess returns in the pre-publication period but negative excess returns in the post-publication period. A limitation of their study is that their analyses relied on only three criteria: sales, BW rank and return on capital, which do not represent completely a firm’s financial health. I replicate Bauman et al.’s study but use a more robust and representative variable set to test the mean reversal hypothesis — Forbes’ financial criteria — and I focus on six variables. In the current study, I look at 4,200 companies listed in Forbes from 1980 to 2000. The results of the expanded study substantiate Bauman et al.’s [2002] study showing that there are positive excess returns in the pre-publication period, but negative excess returns in the post-publication period. An expanded future study will look at five additional variables to see if they make a significant difference on the effects of the returns of small growth stocks.     

Corrigendum to “When is efficiency separable from distribution in the provision of club goods?” [Journal of Economic Theory 90 (2000) 204-221]

This note corrects a slip in Fraser's (J. Econ. Theory 90 (2000) 204-221) treatment of the necessary condition for partial separation of efficiency from distribution in providing a club good. His corrected Theorem 1 shows that many families of utility function can generate partial (and total) separation, thereby considerably extending the scope of his analysis.     

Deregulation, market power and risk behaviour in Spanish banks

This paper provides empirical evidence on the effects of regulatory changes in the market power of Spanish banks. It also analyses the response of banks, in terms of risk-taking behaviour, as a result of a reduction in economic profits. We find that liberalisation measures have increased competition and eroded banks’ market power. We observe that banks with lower charter values tend to have lower equity-assets ratios (lower solvency) and to experience higher credit risk. The last evidence is new in the literature and calls for strengthening regulatory concerns about credit risk management by banks in situations of increased competition.     

中国移动运营市场竞争格局情景分析

中国的移动运营市场一直是中国移动(2000年前为中国电信)和联通两家的双寡头竞争格局.鉴于情景分析法的特点和移动运营市场面临的形势,对移动运营市场后3G时代的竞争格局分析适宜采用情景分析法来预测中国进入3G时代后移动运营市场的几种竞争格局.并可以对每种格局产生的可能性、途径以及各种情景所带来的后果进行详细的比对,这样对我国移动运营市场的健康良性发展可提供一些有益的决策参考.