A Continuous-Time Optimal Insurance Design with Costly Monitoring

We provide a theoretical and numerical framework to study optimal insurance design under asymmetric information. We consider a continuous-time model where neither the efforts nor the outcome of an insured firm are observable to an insurer. The insured may then cause two interconnected information problems: moral hazard and fraudulent claims. We show that, when costly monitoring is available, an optimal insurance contract distinguishes the one problem from the other. Furthermore, if the insured’s downward-risk aversion is weak and if the participation constraint is not too tight, then a higher level of the monitoring technology can mitigate both problems.     

The Instantaneous Volatility and the Implied Volatility Surface for a Generalized Black–Scholes Model

Takaoka (Asia–Pacific Financial Markets 11:431–444, 2004) proposed a generalization of the Black–Scholes stock price model by taking a weighted average of geometric Brownian motions of different variance parameters. The model can be classified as a local volatility model, though its local volatility function is not explicitly given. In the present paper, we prove some properties concerning the instantaneous volatility process, the implied volatility curve, and the local volatility function of the generalized model. Some numerical computations are also carried out to confirm our results.     

Is there a safety premium in the design of corporate bond contracts?

This study examines empirically whether there is a safety premium in the design of bond contracts by highlighting a safety attribute of general mortgage bonds in Japan, which can give especially strong protection to bondholders, who would have priority in the event of legal liquidation. The effects of a safety attribute were not prominent at first in the difference-in-differences analysis. However, the methods for analysing selectivity bias allow us to provide a safety premium in the design of bond contracts, such as lower spread, lower commission, and larger issue size. The resulting bias would depend on the reputation of the bookrunner. This study uncovers the underlying link for the connection between a safety attribute and the observed and unobserved issuer and bookrunner characteristics, to indicate that a safety premium is related to various terms of bond contracts, including the bookrunner-issuer match.     

On the Pricing of Defaultable Bonds Using the Framework of Barrier Options

In the framework of the structural approach of bond pricing, we extend the Fujita–Ishizaka model by considering more realistic payoffs. The payoff to the bondholder at time of default, provided that default occurs prior to maturity, depends on the firm value at time of default. We also find the new measure with the advantage to calculate the value of bond and its financial interpretation. In addition, we present some numerical exmaples.     

Effects of a blocking patent on R&D with endogenous survival activities

This study analyzes the effect of strengthening patent protection for innovation and economic growth by introducing a blocking patent into the endogenous growth model developed by Furukawa (Econ Lett 121(1):26–29, 2013a), which features survival activity of patent holders in the R&D sector with a variety-expansion model. Results show that strengthening patent protection can raise the economic growth rate and social welfare through an endogenous survival investment. Additionally, this study examines the effects of increasing subsidies for R&D. We find that increasing R&D subsidy rate can negatively affect economic growth and social welfare because of the investment for survival activities. This result shows the novel role of a blocking patent in determining innovation effects of R&D subsidies. Furthermore, we analyze the effect of patent breadth which is another patent instrument in this model on innovation and economic growth. Results show that the growth and welfare effects of the profit-division rule and the subsidy rate for R&D may vary with the size of patent breadth.     

A note on the condition of no unbounded profit with bounded risk

As a corollary to Delbaen and Schachermayer’s fundamental theorem of asset pricing (Delbaen in Math. Ann. 300:463–520, 1994; Stoch. Stoch. Rep. 53:213–226, 1995; Math. Ann. 312:215–250, 1998), we prove, in a general finite-dimensional semimartingale setting, that the no unbounded profit with bounded risk (NUPBR) condition is equivalent to the existence of a strict sigma-martingale density. This generalizes the continuous-path result of Choulli and Stricker (Séminaire de Probabilités XXX, pp. 12–23, 1996) to the càdlàg case and extends the recent one-dimensional result of Kardaras (Finance and Stochastics 16:651–667, 2012) to the multidimensional case. It also refines partially the second main result of Karatzas and Kardaras (Finance Stoch. 11:447–493, 2007) concerning the existence of an equivalent supermartingale deflator. The proof uses the technique of numéraire change.