Hepatocellular carcinoma: Prospective assessments of the T-factor with CT,US, and MR imaging

The capabilities of computed tomography (CT), ultrasonography (US), and magnetic resonance (MR) imaging were studied in order to determine the role of each of these noninvasive examinations for estimating the T-factor of hepatocellular carcinomas (HCCs). Fifty-one patients with surgically proven HCCs received CT (50 patients), US (46 patients), and MR (44 patients). The images of CT, US, and MR were prospectively evaluated for main tumor size, intrahepatic metastases, and vascular invasion, which compose the T-factor of HCC, and compared to pathological results. The sizes of the main tumor were estimated correctly by all examinations. For estimating intrahepatic metastases, US (74%) and MR (73%) were superior to CT (65%). For estimating portal invasion, CT (79%) was superior to US (70%) and MR (66%), because CT could demonstrate the segmental staining caused by portal invasion. The estimates of hepatic venous invasion were difficult during any of the examinations. We conclude that presurgical evaluations of the T-factor require the use of US and CT or MR and CT.     

Trading and Ordering Patterns of Market Participants in High Frequency Trading Environment: Empirical Study in the Japanese Stock Market

In this study, we investigate ordering patterns of different types of market participants in Tokyo Stock Exchange (TSE) by examining order records of the listed stocks. Firstly, we categorize the virtual servers in the trading system of TSE, each of which is linked to a single trading participant, by the ratio of cancellation and execution in the order placement as well as the number of executions at the opening of the afternoon session. Then, we analyze ordering patterns of the servers in the categories in short intervals for the top 10 highest trading volume stocks. By classifying the intervals into four cases by returns, we observe how different types of market participants submit or execute orders in the market situations. Moreover, we investigate the shares of the executed volumes for the different types of servers in the swings and roundabouts of the Nikkei 225 index, which were observed in September in 2015. The main findings of this study are as follows: Server type A, which supposedly includes non-market making proprietary traders with high-speed algorithmic strategies, executes and places orders along with the direction of the market. The shares of the execution and order volumes along with the market direction increase when the stock price moves sharply. Server type B, which presumably includes servers employing a market making strategy with high cancellation and low execution ratio, shifts its market making price ranges in the rapid price movements. We observe that passive servers in Server type B have a large share and buy at low levels in the price falls. Also, Server type B, as well as Server type A, makes profit in the price falling days and particularly, the aggressive servers in the server type make most of the profit. Server type C, which is assumed to include servers receiving orders from small investors, constantly has a large share of execution and order volume.     

Consensus building in safety and security: a case study of Fukushima evacuees returning home

This study examines consensus building in environmental and energy policies by analyzing the minutes of the safety and security committee of the Nuclear Regulation Authority (NRA) of the Japanese government, in the context of the discussion of the safe return of Fukushima evacuees after the 2011 Great East Japan Earthquake and Tsunami and the subsequent Fukushima nuclear disaster. One important issue associated with evacuation policies was the high number of evacuees, if not all, who were not willing to return to their old homes. Although the contents of governmental committee meetings are freely accessible through the internet, they have been rarely analyzed for these purposes. In this study, we used text-mining techniques to analyze NRA committee minutes quantitatively and qualitatively. We have three primary findings. First, the committee attempted to take evacuees’ feelings into account and pragmatically discuss what was needed to restore their lives and livelihoods, as well as to make its meetings transparent and open to the public by, for example, streaming them live on the internet. Second, in earlier committee meetings, government representatives insisted on specific policies made by themselves to control the return of evacuees. However, outside experts at the meetings convinced representatives that decisions regarding issues surrounding the safe return of evacuees should consider the opinions of the evacuees themselves. Third, the NRA reported the outcome of the meetings at a Cabinet meeting to accelerate policies requiring urgent implementation as well as those related to the alleviation of people’s anxieties regarding exposure to radioactivity or those related to equal treatment among those who wanted to voluntarily move away from the affected areas versus those who want to return to their homes. Finally, this analysis further identified a number of issues concerning citizen participation and governance associated with environment and energy policies, all of which need to be overcome in order to establish consensus among concerned stakeholders.     

Increasing marginal costs and satiation in the private provision of public goods: group size and optimality revisited

It is widely recognized that the degree of inefficiency in the voluntary provision of a public good increases with the group size of an economy. However, we find that only a slight modification in the conventional assumptions gives rise to a profound difference in outcome. In particular, we show that there is a case where the Nash equilibrium provision and the efficient provision will converge as the size of an economy grows. To show this, we assume individuals face increasing marginal cost of voluntary provision and their preference function has a finite satiety point.      

SCIENTIFIC BREAKTHROUGHS AND NETWORKS IN THE CASE OF SEMICONDUCTOR LASER TECHNOLOGY IN THE US AND JAPAN, 1960s–2000s

United States organisations took a clear lead in semiconductor laser research until the mid‐1970s. After the 1980s, many important breakthroughs were developed by Japanese organisations. Exploring the journal Applied Physics Letters, this study examines how semiconductor laser technology developed in these two countries and how this change in the country‐level industrial leadership in the scientific research occurred. Examining the relationship among industrial organisations, research networks, and scientific breakthroughs, it discusses how these coevolved and how breakthroughs were channelled in different directions. R&D targets were channelled into small markets in the US, but were concentrated into the same markets in Japan.     

Productivity dispersion: facts,theory, and implications

This paper discusses the stylized facts, the theory, and the remaining problems of productivity dispersion, which is essentially related to the concept of equilibrium in the neoclassical theory. Empirical study of data relating to Japanese firms shows that they all obey the Pareto law, and also that the Pareto index decreases with the level of aggregation. In order to explain these two stylized facts we propose a theoretical framework built on the basic principle of statistical physics and on the concept of superstatistics, an approach that accommodates fluctuations of aggregate demand. We show that the allocation of production factors depends crucially on the level of aggregate demand, and that the higher the level of aggregate demand, the closer the economy is to the frontier of the production possibility set.     

Vertical trade and free trade agreements

We investigate the effects of free trade agreements (FTAs) on tariffs and welfare in vertical trade. We consider a three-country model, where an FTA is formed between a country exporting a final good and a country exporting an intermediate good. The FTA unambiguously leads to a reduction in the member country’s tariff, but may cause the non-member country’s tariff level to increase. In the case, where FTA raises the non-member country’s tariff level, the FTA increases that country’s welfare. In contrast, the FTA may render its member countries better off. This result implies that the formation of an FTA may not always be Pareto-improving.     

Optimal inflation target under uncertainty

We derive an optimal state-contingent inflation target in an economy under uncertainty. This inflation target can improve inefficiencies stemming from two sources: the lack of commitment to predetermined policies and the lack of coordination between the monetary and fiscal authorities. We then discuss the pros and cons of our proposal compared with the solution proposed by Beetsma and Bovenberg [Beetsma, R.M.W.J., Bovenberg, A.L., 2001. When does an inflation target yield the second best? Scandinavian Journal of Economics 103, 119–126], paying special attention to their practical feasibility. We will show that in some countries where there is a highly independent central bank, our proposal is more attractive.