Edgeworth rejective core and dividends equilibria of satiated exchange economies

For an exchange economy, under assumptions which did not bring about the existence of equilibrium with dividends as yet, we prove the non-emptiness of the Edgeworth rejective core. Then, via  and ’s decentralization result, we solve the equilibrium with dividends existence problem. Adding to the same assumptions a weak non-satiation condition which differs from the weak non-satiation assumption introduced by Allouch and Le Van (2009), we show in the last section the existence of a Walrasian quasiequilibrium. This result, which fits with exchange economies whose consumers’ utility functions are not assumed to be upper semicontinuous, complements the one obtained by Martins-da-Rocha and Monteiro (2009).     

Product market deregulation and the US employment miracle

We consider the dynamic relationship between product market entry regulation and equilibrium unemployment. The main theoretical contribution is combining a job matching model with monopolistic competition in the goods market and individual bargaining. We calibrate the model to US data and perform a policy experiment to assess whether the decrease in trend unemployment during the 1980s and 1990s could be directly attributed to product market deregulation. Under our baseline calibration, our results suggest that a decrease of less than two-tenths of a percentage point of unemployment rates can be attributed to product market deregulation, a surprisingly small amount.     

The Effects of Guilt-Appeal Intensity on Persuasive and Emotional Outcomes: The Moderating Role of Sponsor Motive

Studies examining the persuasive effects of guilt appeals have yielded mixed results. The current study hypothesizes that source motive (profit versus not for profit) is a key moderating variable underlying these inconsistences. A controlled experiment tested the moderating role of sponsor motive on the relationship between guilt-appeal intensity and persuasiveness of the appeal and ad liking. Findings confirmed the notion that sponsor motive moderates the effects of guilt appeals: When guilt appeals are commercially oriented there is a relative failure of high-intensity guilt appeals compared to moderate-intensity guilt appeals. Moderate-intensity guilt appeals cause more-positive brand attitudes than high-intensity appeals. Yet, when guilt appeals are nonprofit, increases in intensity of guilt communicated lead to positive results. As the guilt-intensity increased, ad liking and persuasiveness increased. It appears that guilt-appeal intensity did not have an effect on brand attitudes when the message was nonprofit.     

No-arbitrage up to random horizon for quasi-left-continuous models

This paper studies the impact, on no-arbitrage conditions, of stopping the price process at an arbitrary random time. As price processes, we consider the class of quasi-left-continuous semimartingales, i.e., semimartingales that do not jump at predictable stopping times. We focus on the condition of no unbounded profit with bounded risk (called NUPBR), also known in the literature as no arbitrage of the first kind. The first principal result describes all the pairs of quasi-left-continuous market models and random times for which the resulting stopped model fulfils NUPBR. Furthermore, for a subclass of quasi-left-continuous local martingales, we construct explicitly martingale deflators, i.e., strictly positive local martingales whose product with the price process stopped at a random time is a local martingale. The second principal result characterises the random times that preserve NUPBR under stopping for any quasi-left-continuous model. The analysis carried out in the paper is based on new stochastic developments in the theory of progressive enlargements of filtrations.     

Robustness of the Black and Scholes Formula

Consider an option on a stock whose volatility is unknown and stochastic. An agent assumes this volatility to be a specific function of time and the stock price, knowing that this assumption may result in a misspecification of the volatility. However, if the misspecified volatility dominates the true volatility, then the misspecified price of the option dominates its true price. Moreover, the option hedging strategy computed under the assumption of the misspecified volatility provides an almost sure one-sided hedge for the option under the true volatility. Analogous results hold if the true volatility dominates the misspecified volatility. These comparisons can fail, however, if the misspecified volatility is not assumed to be a function of time and the stock price. The positive results, which apply to both European and American options, are used to obtain a bound and hedge for Asian options.     

On arbitrages arising with honest times

In the context of a general continuous financial market model, we study whether the additional information associated with an honest time τ gives rise to arbitrage profits. By relying on the theory of progressive enlargement of filtrations, we explicitly show that no kind of arbitrage profit can ever be realised strictly before τ, whereas classical arbitrage opportunities can be realised exactly at τ as well as after τ. Moreover, arbitrages of the first kind can only be obtained by starting to trade as soon as τ occurs. We carefully study the behavior of local martingale deflators and consider no-arbitrage-type conditions weaker than no free lunch with vanishing risk.     

Hedging of a credit default swaption in the CIR default intensity model

An important issue arising in the context of credit default swap (CDS) rates is the construction of an appropriate model in which a family of options written on credit default swaps, referred to hereafter as credit default swaptions, can be valued and hedged. The goal of this work is to exemplify the usefulness of some abstract hedging results, which were obtained previously by the authors, for the valuation and hedging of the credit default swaption in a particular hazard process setup, namely, the CIR default intensity model.