A risk-sensitive stochastic control approach to an optimal investment problem with partial information

We consider an infinite time horizon optimal investment problem where an investor tries to maximize the probability of beating a given index. From a mathematical viewpoint, this is a large deviation probability control problem. As shown by Pham (in Syst. Control Lett. 49: 295–309, 2003; Financ. Stoch. 7: 169–195, 2003), its dual problem can be regarded as an ergodic risk-sensitive stochastic control problem. We discuss the partial information counterpart of Pham (in Syst. Control Lett. 49: 295–309, 2003; Financ. Stoch. 7: 169–195, 2003). The optimal strategy and the value function for the dual problem are constructed by using the solution of an algebraic Riccati equation. This equation is the limit equation of a time inhomogeneous Riccati equation derived from a finite time horizon problem with partial information. As a result, we obtain explicit representations of the value function and the optimal strategy for the problem. Furthermore we compare the optimal strategies and the value functions in both full and partial information cases.

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The Pricing Formula for Commodity-Linked Bonds with Stochastic Convenience Yields and Default Risk

At the maturity, the owner of a commodity-linked bond has the right to receive the face value of the bond and the excess amount of spot market value of the reference commodity bundle over the prespecified exercise price. This payoff structure is an important characteristic of the commodity-linked bonds. In this paper, we derive closed pricing formulae for the commodity-linked bonds. We assume that the reference commodity price and the value of the firm (bonds' issuer) follow geometric Brownian motions and that the net marginal convenience yield and interest rate follow Ornstein–Uhlenbech processes. In the appendix, we derive pricing formulae for bonds which are the same as the above commodity-linked bonds, except that the reference commodity price in the definition of the payoff at the maturity is replaced by the value of a special asset which depends on the convenience yield. This revised version was published online in August 2006 with corrections to the Cover Date.     

A market model with medium/long-term effects due to an insider

In this article, we consider a modification of the Karatzas–Pikovsky model of insider trading. Specifically, we suppose that the insider agent influences the long/medium-term evolution of Black–Scholes type model through the drift of the stochastic differential equation. We say that the insider agent is using a portfolio leading to a partial equilibrium if the following three properties are satisfied: (a) the portfolio used by the insider leads to a stock price which is a semimartingale under his/her own filtration and his/her own filtration enlarged with the final price; (b) the portfolio used by the insider is optimal in the sense that it maximises the logarithmic utility for the insider when his/her filtration is fixed; and (c) the optimal logarithmic utility in (b) is finite. We give sufficient conditions for the existence of a partial equilibrium and show in some explicit models how to apply these general results.     

A NEOCLASSICAL FOUNDATION OF THE NON-LINEAR INPUT-OUTPUT MODEL

A non-linear input-output system is constructed on the basis of neoclassical production technologies. Four results are reported: (i) there exists a unique solution to the developed input-output system; (ii) every real square matrix can be the Jacobi matrix of the function relating gross outputs to net outputs; (iii) if the system has a solution at a final demand vector, there is a solution at every final demand vector near it; and (iv) when the final demand for a commodity increases, its price never decreases. The system is founded on a profit function of the economy, which represents a neoclassical production possibility. By this treatment, the system can deal with joint productions, as well as no-joint productions.     

A dynamic generalization of the tobin model

The paper studies the stability and the non-neutrality of money issues of the neoclassical monetary growth theory when the liquidity preference function and the price dynamics equation are generalized in the Tobin model. Our generalization introduces Tobin's real purchasing power into the liquidity preference function, thereby allowing real balance flows to exert direct income effects. Such effects allow a number of separate cases in the price dynamics behavior, some of which lead to results that differ from the neoclassical propositions. Thus, these propositions are sensitive to the choice of a particular proxy measure of the transactions motives of the demand for money.     

Japan-India civil nuclear energy cooperation: prospects and concerns

India is a non-party to the Nuclear Non-Proliferation Treaty. However, India argues its impeccable non-proliferation record shows the country as a responsible state with advanced nuclear technology that should be allowed to acquire the same benefits and advantages of nuclear energy cooperation under the existing global nuclear non-proliferation regime. This statement needs careful analysis of whether or not the Japan-India civil nuclear energy cooperation agreement could be successfully concluded and acceded to. This paper elaborates on the possibilities and concerns related to the matter from a politico-legal point of view, in order to materialise a mutually satisfactory and legitimate bilateral agreement. The scope of possible civil nuclear energy cooperation may be limited, probably not exceeding the level that the US has agreed with India, right now. It is, however, a necessary initial step for dramatically reconstructing our relationship, which may allow for greater cooperation in the near future.     

Hedge Fund Activism in Japan under the Stewardship and Corporate Governance Codes

This study focuses on activist funds during the second wave of activism after the implementation of the Stewardship and Corporate Governance Codes in Japan. Based on reports of large-scale shareholdings (acquisitions of 5% shares or more) submitted by activist funds between 2014 and 2019, this study finds that the stock returns of target firms react positively to the intervention of activist funds. The positive correlation intensifies for funds classified as hostile or domestic. Unlike in the first wave of activism, activist funds do not necessarily target low-margin or undervalued firms in the second wave of activism. Comparing financial indicators of the targets of the pre- and post-acquisition periods of large blocks of shares by activist funds, return on assets tends to decline more than that of their matching peer control firms, while the dividend payout ratio tends to rise more. This study contributes to the related research in three ways. First, this study adds empirical evidence on hedge fund activism outside the U.S., which is still somewhat scant. Second, this study is the first in the English or Japanese language literature to focus on the second wave of activism in Japan. Third, this study presents empirical results that are distinct from those in prior studies focusing on the first wave, perhaps because institutional changes forced activist funds to focus more on engagement rather than selecting cheap firms.

     

Conflict,growth, distribution,and employment: a long-run Kaleckian model

This paper presents a Kaleckian growth model in which (i) the rate of capacity utilization, the profit share, and the rate of employment are adjusted in the medium run, and (ii) the normal rate of capacity utilization and the expected rate of capital accumulation are adjusted in the long run. The long-run equilibrium is a continuum of equilibria and is characterized by hysteresis in that the long-run position of the economy depends on where it starts. An increase in the bargaining power of workers lowers the rate of unemployment in both the medium-run and the long-run equilibrium.