Shortlisting procedure with a limited capacity

A decision maker, who is overwhelmed by the number of available alternatives, limits her consideration. We investigate a model where a decision maker’s capacity determines whether she is overwhelmed: She considers all the available alternatives if their number does not exceed her capacity; otherwise, she applies a shortlisting procedure to reduce the number of alternatives to within her capacity. We show how to deduce the decision maker’s capacity, her preference and the alternatives that she considers from the observed behavior. Furthermore, we provide the necessary and sufficient conditions for a consideration function to be derived by the shortlisting procedure with a limited capacity.     

A model of stochastic choice from lists

We study stochastic choice from lists. All lists present the same set of alternatives albeit in different orders. Faced with a list, the decision maker makes her choice in two stages. In the first stage she searches through the list till she sees $k$ alternatives. In the second stage she chooses from the alternatives she has seen. Both $k$ and the choice rule governing her second stage behavior are random. We show that the underlying primitives of our model are revealed by the decision maker’s choice frequencies from lists. We characterize the model and two of its special cases. In the first special case the decision maker deterministically chooses the best observed alternative according to a given preference. In the second, the decision maker maximizes random preferences.     

Crisp monetary acts in multiple-priors models of decision under ambiguity

In axiomatic models of decision under ambiguity using a set of priors, a clear distinction can be made between acts which are affected by ambiguity and those which are not: the crisp acts. In these multiple-priors models, the decision maker is indifferent between holding a constant act or holding a non constant crisp act with the same expected utility, if it exists. In financial settings, we show that this indifference, together with the standard definition of monetary acts in the Anscombe–Aumann framework, implies that the investor ignores the variance of some assets, a behavior which conflicts with the assumption on which modern portfolio theory has been built. In this paper we establish the geometrical and topological properties of the set of priors that rule out the existence of non constant crisp acts. These properties in turn restrict what can possibly be an unambiguous financial asset.     

Asset price volatility and banks

This paper examines the operation of Diamond–Dybvig banks when depositors have access to the asset market. Previous studies have shown that banks are redundant in this environment since it is impossible to prevent the strategic withdrawals. This paper shows that the strategic withdrawals can be prevented if the market risk, due to asset price volatility, is considered. Banks provide deterministic returns to the depositors since the aggregate withdrawals are predictable, and therefore, banks can choose the portfolio such that no asset liquidation is involved. However, an individual consumer with stochastic liquidity need is vulnerable to the price volatility if he holds the asset directly. Therefore, banks improve the consumers’ welfare by providing the insurance against not only the liquidity shock but also the market risk. Banks are not redundant.     

Similarity-based mistakes in choice

We characterize the following choice procedure. The decision maker is endowed with two binary relations over alternatives, a preference and a similarity. In every choice problem she includes in her choice set all alternatives which are similar to the best feasible alternative. Hence she can, by mistake, choose an inferior option because it is similar to the best. We characterize this boundedly rational behavior by suitably weakening the rationalizability axiom of Arrow (1959). We also characterize a variation where the decision maker chooses alternatives on the basis of their similarities to attractive yet infeasible options. We show that similarity-based mistakes of either kind lead to cyclical behavior. Finally, we reinterpret our procedure as a method for choosing a bundle given a set of individual items, in which the decision maker combines the best feasible item with those that complement it.     

Bank valuation in new EU member countries

This paper studies the role of institutional reforms in affecting bank valuation in new European Union (EU) member countries. It takes advantage of the dynamic nature of institutional reforms in transition economies and explores the causal effects of those reforms on banks’ Tobin's Q over the period of 1997–2008. Using a difference-in-difference approach, the paper shows that Tobin's Q increases substantially after these countries reform their legal institutions and liberalize banking. However, it decreases after stock market reforms. After further examination of the interactive relationships between different reforms and bank valuation, it is observed that when the banking reform is well implemented, legal reform can have a stronger impact on banks’ Tobin's Q. On the other hand, banking reform and security market reform has a substitutive relationship. The analysis also suggests that foreign ownership, market power, and asset diversification significantly affect Tobin's Q. These results are robust even after simultaneously controlling for equity risk.     

A flexible lattice framework for valuing options on assets paying discrete dividends and variable annuities embedding GMWB riders

In a market where a stochastic interest rate component characterizes asset dynamics, we propose a flexible lattice framework to evaluate and manage options on equities paying discrete dividends and variable annuities presenting some provisions, like a guaranteed minimum withdrawal benefit. The framework is flexible in that it allows to combine financial and demographic risk, to embed in the contract early exercise features, and to choose the dynamics for interest rates and traded assets. A computational problem arises when each dividend (when valuing an option) or withdrawal (when valuing a variable annuity) is paid, because the lattice lacks its recombining structure. The proposed model overcomes this problem associating with each node of the lattice a set of representative values of the underlying asset (when valuing an option) or of the personal subaccount (when valuing a variable annuity) chosen among all the possible ones realized at that node. Extensive numerical experiments confirm the model accuracy and efficiency.

     

An equilibrium model of insider trading in continuous time

We study a Bayesian–Nash equilibrium model of insider trading in continuous time. The supply of the risky asset is assumed to be stochastic. This supply can be interpreted as noise from nonrational traders (noise traders). A rational informed investor (the insider) has private information on the growth rate of the dividend flow rewarded by the risky asset. She is risk averse and maximizes her inter-temporal utility rate over an infinite time-horizon. The market is cleared by a risk neutral market maker who sets the price of the risky asset competitively as the conditional present value of future dividends, given the information supplied by the dividend history and the cumulative order flow. Due to the presence of noise traders, the market demand does not fully reveal the insider’s private information, which slowly becomes incorporated in prices. An interesting result of the paper is that a nonstandard linear filtering procedure gives an a priori form for the equilibrium strategy to be postulated. We show the existence of a stationary linear equilibrium where the insider acts strategically by taking advantage of the camouflage provided by the noise which affects the market maker’s estimates on private information. In this equilibrium, we find that the insider’s returns on the stock are uncorrelated over long periods of time. Finally, we show that the instantaneous variance of the price under asymmetric information lies between the instantaneous variance of the price under complete and incomplete information. The converse inequalities hold true for the unconditional variance of the price.     

Optimal decisions in foreign exchange bidding markets

I characterize optimal bidding decisions in bidding markets where each agent does not perceive she can significantly affect the market outcome. Using a foreign exchange bidding framework to provide a micro-foundation for the shape of a bidder's payoff function, I show that (1) in a discriminatory auction a bidder bids for a price that equals the value of the marginal product of her bid quantity, and (2) in a competitive auction a bidder bids for a price that equals the value of the average product of her bid quantity. An example illustrates the comparative properties of these solutions.     

Career Concerns and Excessive Risk Taking

In a seminal paper, Holmström ( 1999 ) shows that an agent who is unsure of her ability and has a payoff linear in her reputation underinvests in risky projects. I show that if the agent privately knows her ability, then the opposite must happen, that is, she always overinvests in risky projects, no matter what the curvature of her payoff in reputation. Moreover, if project quality is verifiable and the agent is uninformed about her ability, then she reveals project quality and first best is attained; but if she privately knows her ability, first best is not attainable and she still overinvests.     

Unravelling financial market linkages during crises

An empirical model of multiple asset classes across countries is formulated in a latent factor framework. A special feature of the model is that financial market linkages during periods of financial crises, including spillover and contagion effects, are formally specified. The model also captures a range of common factors including global shocks, country and market shocks, and idiosyncratic shocks. The framework is applied to modelling linkages between currency and equity markets during the East Asian financial crisis of 1997–98. The results provide strong evidence that cross‐market links are important. Spillovers have a relatively larger effect on volatility than contagion, but both are statistically significant. Copyright © 2007 John Wiley & Sons, Ltd.     

Understanding continuity in public sector HRM through neo‐institutional theory: why national collective bargaining has survived in English local government

Most HRM research over recent decades has concentrated on ‘change’, charting ever more fragmented, individualised and unitarist employment relationships. This is equally true of public sector HRM, where the emphasis has been on neo‐liberalism and marketisation. However, in many countries and sectors, collective, pluralist approaches to HRM and industrial relations have proved remarkably resilient. This article uses Neo‐Institutional theory to explain the ‘continuity’ of one such HRM system: national collective bargaining in English local government (1979–2007). We argue that this survives because it manages the political and managerial processes that link central government and central–local relations and acts as a conduit between institutional stakeholders to deliver services to the public. By understanding the ‘passive consensus’ that holds the collectivist HRM system together, we can anticipate the forces that might pull it apart.     

Margin trade,short sales and financial stability

We model how leveraged trading activities constrained by dynamic funding availability affect financial stability. In the market, customers trade based on the fundamental value of the risky asset and make full payment for their transactions, while speculators take trading position based on margin, which is constantly adjusted by the financier, the fund provider, according to the price volatility. As a result of equilibrium price discontinuity triggered by dynamic margin requirements, trivial shocks to external supply, wealth or fundamental value can be transmitted into asset price crashes or jumps. We find that tightening margin requirements improves (mitigates) the market liquidity in the bull (bear) market, and that imposing short sale constraints helps prevent the price from falling further when the asset is sufficiently under-priced and accelerate price collapse when the asset is over-priced.

     

Satisficing with a variable threshold

We axiomatize a model of satisficing which features random thresholds and the possibility of choice abstention. Given a menu, the decision maker first randomly draws a threshold. Next, using a list order, she searches the menu for alternatives which are at least as good as the threshold. She chooses the first such alternative she finds, and if no such alternative exists, she abstains. Since the threshold is random, so is the resulting behavior. We characterize this model using two simple axioms. In general the revelation of the model’s primitives is incomplete. We characterize a specialization of the model for which the underlying preference and list ordering are uniquely identified by choice frequencies. We also show that our model is a special Random Utility Model.     

Stock market dynamics with institutional trading

In this paper, the impact of institutional trading on stock market dynamics is analysed. We study the problem in an abstract context in which stocks of only one type are traded and institutions' portfolio choices are simply restricted to the partition of portfolio between stocks and bonds; in this simplified context it is shown how institutions' monitoring of individual investors' potentially destabilizing behavior (hearding and positive-feedback behavior) can be effective to obtain stock market stability.

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Sommario In questo articolo abbiamo analizzato la dinamica del mercato azionario in presenza di fondi di investimento. A tal fine, è stato proposto e studiato un modello dinamico che evidenzia alcuni nessi causali fra le scelte dei fondi e le scelte degli investitori non istituzionali.

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While remaining fully rsponsible for this paper, I thank Marcello Galeotti, Antonio Gay and Franco Gori for insightful comments and suggestions.     

Effects of brand-related and market signals on franchisees’ entrepreneurial decisions: a multi-country panel data analysis

This paper analyses the influence of market and brand-related signals on franchisees’ decisions when choosing a franchise brand with which to open an outlet for the first time. Panel data methodology was used to analyse a sample of 1277 chains operating in Spain, Mexico and Peru between 2004 and 2013. The results show that market signals prevail over brand-related signals. Within brand-related signals, franchisees first seek information relating to the brand’s sector and then seek information relating to the brand’s value. Franchisors should match the content of the signals they send to the market to the true characteristics of the franchise. Franchisors should also endeavour to ensure the country where they operate has general and franchise-specific legislation that fosters business activity by both franchisor and franchisee. The use of institutional quality as a signal in a multi-country study represents a significant contribution to the literature on franchising.

     

Ellsberg’s two-color experiment,portfolio inertia and ambiguity

Results in this paper relate the observation of an interval of prices at which a decision maker (DM) strictly prefers to hold a zero position on an asset (termed “portfolio inertia”) to the DM’s perception of the underlying payoff relevant events as ambiguous, as the term is defined in [Econometrica 69 (2001) 265]. The connection between portfolio inertia and ambiguity is established without invoking a parametric preference form, such as the Choquet expected utility or the max–min multiple priors model. This allows us to draw an observable distinction between portfolio inertia that may arise purely due to first-order risk aversion type effects, such as those which could arise even if preferences were probabilistically sophisticated, and portfolio inertia that involves ambiguity perceptions.     

Prospect Theory in the Heterogeneous Agent Model

Using the Heterogeneous Agent Model framework, we incorporate an extension based on Prospect Theory into a popular agent-based asset pricing model. This extension covers the phenomenon of loss aversion manifested in risk aversion and asymmetric treatment of gains and losses. Using Monte Carlo methods, we investigate behavior and statistical properties of the extended model and assess how our extension is manifested in different strategies. We show that, on the one hand, the Prospect Theory extension keeps the essential underlying mechanics of the model intact, but on the other hand it considerably changes the model dynamics. Stability of the model is increased and fundamentalists may be able to survive in the market more easily. When only the fundamentalists are loss-averse, other strategies profit more.

     

Inventory management effects,isolated: Evidence from the federal funds market

The federal funds market is highly competitive, has uniform information, and does not have most order-processing cost components of equity markets. Hence, it provides an opportunity to study the effect of inventory management on the bid-ask spread in an isolated fashion. Using a unique data set of daily borrowing and lending federal funds quotes posted by a large commercial bank, we find that the bank maintains a fairly constant bid-ask spread throughout a two-week reserve maintenance period. It acts similarly to a market maker facilitating flow of funds between depository institutions throughout the reserve maintenance period. The bank becomes more active toward the end of the period. In particular, on settlement Wednesday it increases the bid and ask quotes relative to the effective federal funds rate in an apparent attempt to manage its reserve inventory and satisfy its own reserve requirements.     

Trade credit versus bank credit: Evidence from corporate inventory financing

In this study, I introduce capital market imperfections into a structure framework of inventory investments and investigate impacts of trade credit on firms’ inventory dynamics and analyze the relationship between trade credit and bank loans. As a result, firms end up using a mix of trade credit and bank loans. I find that the use of trade credit and bank credit can be either complements or substitutes. During tight monetary periods, trade credit operates mainly as a substitute for bank borrowing while during looser monetary episodes even when the economy is weak, trade credit and bank loans are dominated by a complementary effect.