Why does junior put all his eggs in one basket? A potential rational explanation for holding concentrated portfolios

Empirical studies of household portfolios show that young households, with little financial wealth, hold underdiversified portfolios that are concentrated in a small number of assets, a fact often attributed to behavioral biases. We present a potential rational alternative: we show that investors with little financial wealth, who receive labor income, rationally limit the number of assets they invest in when faced with financial constraints such as margin requirements and restrictions on borrowing. We provide theoretical and numerical support for our results and identify the ratio of financial wealth to labor income as a useful control variable for household portfolio studies.     

Learning from peers' stock prices and corporate investment

Peers' valuation matters for firms' investment: a one standard deviation increase in peers' valuation is associated with a 5.9% increase in corporate investment. This association is stronger when a firm's stock price informativeness is lower or when its managers appear less informed. Also, the sensitivity of a firm's investment to its stock price is lower when its peers' stock price informativeness is higher or when demands for its products and its peers' products are more correlated. Furthermore, the sensitivity of firms' investment to their peers' valuation drops significantly after going public. These findings are uniquely predicted by a model in which managers learn information from their peers' valuation.     

Strategic loan defaults and coordination: An experimental analysis

This paper experimentally studies the impact of bank and borrower fundamentals on loan repayment. We find that solvent borrowers are more likely to default strategically when the bank’s expected strength is low, although loan repayment is a Pareto dominant Nash equilibrium. Borrowers are also less likely to repay when other borrowers’ expected repayment capacity is low, regardless of banks’ fundamentals. We show that changes in expectations about bank and borrower fundamentals change the risk dominance properties of the borrowers’ coordination problem, and that these changes subsequently explain strategic defaults. For the individual borrower, loss aversion and negative past experiences reduce repayment, suggesting that bank failure can be contagious in times of distress.     

Conditional Value-at-Risk,spectral risk measures and (non-)diversification in portfolio selection problems – A comparison with mean–variance analysis

We study portfolio selection under Conditional Value-at-Risk and, as its natural extension, spectral risk measures, and compare it with traditional mean–variance analysis. Unlike the previous literature that considers an investor’s mean-spectral risk preferences for the choice of optimal portfolios only implicitly, we explicitly model these preferences in the form of a so-called spectral utility function. Within this more general framework, spectral risk measures tend towards corner solutions. If a risk free asset exists, diversification is never optimal. Similarly, without a risk free asset, only limited diversification is obtained. The reason is that spectral risk measures are based on a regulatory concept of diversification that differs fundamentally from the reward-risk tradeoff underlying the mean–variance framework.     

Liquidity uncertainty and intermediation

The paper performs a welfare comparison between demand deposit and equity contracts in the presence of intrinsic aggregate uncertainty. In this framework, the welfare dominance of deposit contracts emerges under corner preferences. It is shown that aggregate uncertainty creates high price volatility of ex-dividend equity claims traded in a secondary market and the resulting consumption allocations offer less risk-sharing opportunities to risk-averse consumers than tailor-made deposit contracts. The contingency of early payoffs on depositors’ withdrawal order reinforces the welfare performance of deposit contracts, whereas costly liquidation of productive long-term investments deteriorates their welfare performance relative to equity contracts.     

Risk and concentration in payment and securities settlement systems

What drives the intraday patterns of settlement in payment and securities settlement systems? Using a model of the strategic interaction of participants in these systems to capture some stylized facts about the Federal Reserve's Fedwire funds and securities systems, this paper identifies three factors that influence a participant's decision on when to send transactions intraday: cost of intraday liquidity, extent of settlement risk, and system design. With these factors, the model can make predictions regarding the impact of policy on the concentration of transactions, amount of intraday overdrafts, central bank credit exposure, costs to system participants, and other risks.     

Assessing the risk-return trade-off in loan portfolios

This paper proposes a methodology to analyse the risk and return of large loan portfolios in a joint setting. I propose a tractable model to obtain the distribution of loan returns from observed interest rates and default frequencies. I follow a sectoral approach that captures the heterogeneous cyclical features of different kinds of loans and yields moments in closed form. I investigate the validity of mean–variance analysis with a value at risk constraint and study its relationship with utility maximisation. Finally, I study the efficiency of corporate and household loan portfolios in an empirical application to the Spanish banking system.     

A Reconsideration of Minsky's Financial Instability Hypothesis

The worst and longest depressions have tended to occur after periods of prolonged, and reasonably stable, prosperity. This results in part from agents rationally updating their expectations during good times and hence becoming more optimistic about future economic prospects. Investors then increase their leverage and shift their portfolios toward projects that would previously have been considered too risky. So, when a downturn does eventually occur, the financial crisis and the extent of default become more severe. Whereas a general appreciation of this syndrome dates back to Minsky (1992) and even beyond, to Irving Fisher ( 1933 ), we model it formally. In addition, endogenous default introduces a pecuniary externality since investors do not factor in the impact of their decision to take risk and default on the borrowing cost. We explore the relative advantages of alternative regulations in reducing financial fragility and suggest a novel criterion for improvement of aggregate welfare.     

Firm age and the evolution of borrowing costs: Evidence from Japanese small firms

This paper investigates how firms’ borrowing costs evolve as they age. Using a new panel data set of about 100,000 bank-dependent small firms for 1997–2002 and focusing on the channel of “adaptation” (i.e., surviving firms’ borrowing costs decline as they age) and that of “selection” (i.e., total borrowing costs decline as defaulting firms exit), we find that the reputation hypothesis suggested by Diamond (1989) provides a more plausible explanation of the downward sloping age profile of borrowing costs than the firm dynamics (Cooley and Quadrini, 2001) or the relationship banking (Boot and Thakor, 1994) hypothesis. In addition, we examine whether the firm selection process in Japan has been natural or unnatural. Our findings suggest that it has been natural in that firms with lower quality are separated, face higher borrowing costs, and are eventually forced to exit, which contrasts with the results of previous studies on credit allocations in Japan, including Peek and Rosengren (2005). Further, we find that the evolution of borrowing costs is partially due to selection but is mainly attributable to adaptation.     

Peer performance and stock market entry

Peer performance can influence the adoption of financial innovations and investment styles. We present evidence of this type of social influence: recent stock returns that local peers experience affect an individual's stock market entry decision, particularly in areas with better opportunities for social learning. The likelihood of entry does not decrease as returns fall below zero, consistent with people not talking about decisions that have produced inferior outcomes. Market returns, media coverage, local stocks, omitted local variables, short sales constraints, and stock purchases within households do not seem to explain these results.     

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.     

Performance evaluation with high moments and disaster risk

Traditional performance evaluation measures do not account for tail events and rare disasters. To address this issue, we reinterpret the riskiness measures of Aumann and Serrano (2008) and Foster and Hart (2009) as performance indices. We derive the moment properties of these indices and their sensitivity to rare disasters and show that they are consistent with the asset pricing literature. As applications, we show that “anomalous” investment strategies such as “momentum” or investment in private equity lose much of their glamour when accounting for high moments and rare events. Furthermore, using the indices to select mutual funds results in desirable high-moment properties out of sample.     

PORTFOLIO OPTIMIZATION UNDER TRACKING ERROR AND WEIGHTS CONSTRAINTS

The performance of active portfolio managers who must comply with a weights constraint is often assessed against a benchmark. The weights constraint is common as the funds are committed by their own prospectus to a minimum (or maximum) portfolio concentration. We characterize the optimal asset allocation and analyze the implications of the weights constraint on the manager's performance and on the relevance of the information ratio. We obtain that because of the weights constraint, at the optimum, the information ratio often decreases when the manager is free to deviate more from the benchmark.     

ON THE LINKAGE BETWEEN FINANCIAL RISK TOLERANCE AND RISK AVERSION

We explore the linkage between financial risk tolerance (FRT) and risk aversion. To do this, we obtain FRT scores from a psychometrically validated survey and conduct a battery of online lottery choice experiments involving the same nonstudent participants. We contrast: real and hypothetical payoffs, low and high stakes, decisions involving gains and losses, and order effects. Our key finding is that the two approaches to analyzing decision making under uncertainty are strongly aligned. We present evidence that this is particularly the case for the female participants in our sample and when high‐stake gambles are employed.     

Portfolio selection with mental accounts and background risk

Das et al. (2010) develop a model where an investor divides his or her wealth among mental accounts with motives such as retirement and bequest. Nevertheless, the investor ends up selecting portfolios within mental accounts and an aggregate portfolio that lie on the mean–variance frontier. Importantly, they assume that the investor only faces portfolio risk. In practice, however, many individuals also face background risk. Accordingly, our paper expands upon theirs by considering the case where the investor faces background risk. 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 show that these portfolios lie away from the mean–variance frontier under fairly general conditions. Third, we find that the composition and location of such portfolios can differ notably from those of portfolios on the mean–variance frontier.