Hajime Oniki

Comparative dynamics (sensitivity analysis) in optimal control theory

Abstract This paper considers an optimal control problem with a parameter and develops a systematic method for comparative dynamics. A sufficient condition for the optimum solution to be differentiable with respect to the parameter is provided. Formulas for computing the derivative are given in the form of initial-value problems of linear differential equations. The possibility of discontinuous optimal controls is fully taken care of. An example of the comparative dynamics is given in terms of a model of optimal capital accumulation.

The productivity effects of the liberalization of Japanese telecommunication policy

In the early 1980s, the Japanese government decided to pursue policies of liberalization that opened Japans telecommunication market to competition and moved toward the privatization of Nippon Telegraph and Telephone (NTT), the dominant domestic telecommunication service provider. The purpose of this paper is to assess the effects of liberalization on the productive performance of NTT. To assess the productive consequences of liberalization, we first provide basic productivity measures for NTT. The Total Factor Productivity (TFP) measures are then decomposed to separate out the effects of liberalization from other factors such as scale, technology, and capacity utilization. The TFP decomposition is based on the parameter estimates of a dynamic cost model.During the 1958–87 period, NTTs TFP level increased at an average annual rate of 3.4%. However, TFP improved at a significantly faster rate following the decision to adopt policies of liberalization. The NTTs average annual TFP growth rate was 5.12% for the 1982–87 period as compared to a 0.26% per year growth rate for the previous five year (1977–82) period. The decomposition of TFP growth appears to indicate that liberalization was a major source of productivity improvement for NTT.

The Cost of Communication in Economic Organization

I. Introduction and background, 529. — II. The model and the approximation of economic data, 534. — III. The cost of communication, 540. — IV. Conclusions and some further remarks, 544. — Appendix A: communication and the amount of information, 546. — Appendix B: proofs, 549.

ICTs and sustainability: The managerial and environmental impact in Japan

There are manifold causal linkages between information and communications technologies (ICTs) and social sustainability. In this article, these linkages are classified into three areas: direct improvement of corporate productivity, changed behaviour of people/organizations, and improved decision‐making capabilities within society. A framework is proposed to analyse the first two of these three linkages, together with the results of a questionnaire survey. These point to a continuous growth trend in Japanese ICT investment with sectoral variations, and statistically significant evidence of ICTs’ contributions to corporate operations and environmental issues.

Potential demand for m-government services in Japan

This article attempts to identify factors that influence the potential demand for m-government service adoption in Japan by analysing survey responses. This study identifies smartphone ownership, mobile application activity and e-government subscription as demand drivers. These results suggest government should encourage Juki cards and the e-tax payment system adoption and support programmes to encourage smartphone ownership and mobile application subscriptions.

Japanese telecommunications as network industry: industrial organization for the BISDN generation technology

Abstract This study proposes a new industrial structure for the Japanese information infrastructure in the 21st century. The proposed industrial organization has a hierarchical structure with five layers, each of which corresponds to a functional description of BISDN technology. Each layer is then assigned a market structure (i.e., competition, regulated competition, or regulated monopoly). The proposed industrial organization can serve as not only a backbone of the BISDN-based information infrastructure but also as a conceptual framework for guiding the NTT divestiture planned for 1995.