A trend filtering method closely related to $$\ell _{1}$$ trend filtering

The filtering method developed by Kim et al. (SIAM Rev 51:339–360, 2009), \(\ell _{1}\) trend filtering, is attractive because it enables us to estimate a continuous piecewise linear trend. This paper introduces a new filtering method closely related to \(\ell _{1}\) trend filtering in order to contribute to the accumulation of knowledge on \(\ell _{1}\) trend filtering. We show that the piecewise linearity, which is the key feature of \(\ell _{1}\) trend filtering, is derived from the new filtering. For this reason, we refer to the filtering as ‘pure’ \(\ell _{1}\) trend filtering. We also demonstrate some other miscellaneous results concerning the new filtering.     

Cointegration and spatial price transmission among wheat and wheat-flour markets in Afghanistan

This article examines cointegration and spatial price transmission among Afghan wheat and flour markets as well as their linkages with those of supplier countries and global markets. Unit root tests, consistent momentum threshold autoregressive (M-TAR) models and vector error correction models (asymmetric and symmetric) are employed to achieve research objectives. The results suggest that provincial wheat and flour markets may have a long-run relationship with principal market of Kabul. Afghan wheat and flour markets may also be cointegrated with their respective global, Kazakh and Pakistani markets. While provincial wheat markets might adjust to divergence from their long-run equilibrium with Kabul wheat market, some of the provincial flour markets may not respond to deviation from their long-run equilibrium with Kabul flour market. The speed of adjustment towards the long-run Afghan–Pakistani and Afghan–Kazakh equilibrium may be faster for Afghan flour than wheat markets. The equilibrium adjustment coefficients are generally small and market imperfections may exist, however. A shock in Kabul wheat and flour markets may have long-lasting effect on the respective provincial markets whereas a shock in global wheat and Pakistani, and Kazakh wheat and flour markets might have transitory effect on the corresponding Afghan markets.     

Agency Contracts,Noncommitment Timing Strategies and Real Options

Given that an owner lacks the ability to commit to his or her timing decisions under a manager's hidden action, we consider the optimal design of the contract and the owner's optimal timing decisions. Using a real options approach, we show that, compared with the full commitment case, a higher (lower)‐quality project is launched later than (at the same time as) the first‐best case, whereas the replacement of the manager is (is not necessarily) made later if the hidden‐action problem is severe enough (is not severe enough). Severance pay may serve to minimize the compensation for the manager's loss of corporate control.     

Implementation of multi-agent incentive contracts with the principal's renegotiation offer

The purpose of this paper is to explore a mechanism for supporting desired equilibrium actions in a one-principal, multi-agent model when the principal makes a renegotiation offer. We show that there exists a mechanism in which the principal's most preferred mixed strategy is always supported. Received: 30 May 1997 / Accepted: 10 October 1998     

Credit rationing and implicit contract theory : An empirical study

This paper investigate whether or not implicit contract relations predominate in the Japanese bank loan market and produce equilibrium credit rationing. The empirical evidence suggests that risks are shared between banks and firms through interest rate arrangements. This implies that commercial banks in Japan operate in a market dominated by implicit contract relations. However, the evidence does not support the view that Japanese commercial banks execute credit rationing in the sense of Fried and Howitt (1980). Furthermore, the results show that large banks differ from small banks in the risk consideration of loan contracts. These empirical results are completely consistent with the intermarket business group hypothesis such that the group formation aims to share risks and profits among members.     

OPTIMAL CONSUMPTION AND PORTFOLIO SELECTION WITH INCOMPLETE MARKETS AND UPPER AND LOWER BOUND CONSTRAINTS

We study an optimal consumption and portfolio selection problem for an investor by a martingale approach. We assume that time is a discrete and finite horizon, the sample space is finite and the number of securities is smaller than that of the possible securities price vector transitions. the investor is prohibited from investing stocks more (less, respectively) than given upper (lower) bounds at any time, and he maximizes an expected time additive utility function for the consumption process. First we give a set of budget feasibility conditions so that a consumption process is attainable by an admissible portfolio process. Also we state the existence of the unique primal optimal solutions. Next we formulate a dual control problem and establish the duality between primal and dual control problems. Also we show the existence of dual optimal solutions. Finally we consider the computational aspect of dual approach through a simple numerical example.     

Bounds on the efficiency of the residual design of extended BIB designs

This gives a complete proof for bounds of the efficiency, conjectured by Das and Kageyama (1992), on robustness of extended balanced incomplete block designs against the unavailability of any number of observations in a block.     

The Role of Network Effects in the US VCR Market, 1978–1986

This paper estimates the importance of indirect network effects in the US video cassette recorder (VCR) market between 1978 and 1986. Estimation reveals the significant role of networks in the format competition between VHS and Beta. The paper also finds that if Sony, the system sponsor of Beta, had aggressively introduced its VCRs at the early stage of competition, Beta would likely have dominated the market in 1985; instead, the format disappeared in 1989. Finally, the paper measures consumer welfare for the value of network effects in VCRs, and assesses the consumer welfare effect of standardization.     

Challenges for policy of network oriented society a Japanese view

Social impacts of digital information networks are described in terms of convergence of service modes, integration of socioeconomic activities, change in industrial structure, strengthening social infrastructure and enrichment of culture, with some reference to specific Japanese situations. Emphasis is placed on such issues as reorganization of regulatory measures, interoperability of systems and services, communities of interest, privacy and security, freedom of information, information resource development, software production, shift of workforce, societal receptivity, preservation and creation of culture, and lowering of language barriers.