The effect of social distancing on the reach of an epidemic in social networks

How does social distancing affect the reach of an epidemic in social networks? We present Monte Carlo simulation results of a susceptible–infected–removed with social distancing model. The key feature of the model is that individuals are limited in the number of acquaintances that they can interact with, thereby constraining disease transmission to an infectious subnetwork of the original social network. While increased social distancing typically reduces the spread of an infectious disease, the magnitude varies greatly depending on the topology of the network, indicating the need for policies that are network dependent. Our results also reveal the importance of coordinating policies at the ‘global’ level. In particular, the public health benefits from social distancing to a group (e.g. a country) may be completely undone if that group maintains connections with outside groups that are not following suit.

     

Japanese marketing in the post-bubble era

This article analyzes recent changes in marketing practices in Japan against the background of the recession and the high yen rate of the early 1990s. Based on direct observation, press reports, and interviews with experts, the study describes the changing situation in the Japanese market and shows how new opportunities for Western companies are opening up. The longer term implications of the home market changes for Japanese companies' competitiveness abroad are also discussed.     

Panel Asymptotics and Statistical Decision Theory

This paper develops some applications of asymptotic statistical decision theory in econometrics, focusing on settings where the data are organized into groups or cells with heterogeneous parameters. Even if the groups are of different sizes, local asymptotic normality holds under suitable regularity conditions, and this can greatly simplify analysis of different types of econometric problems. We apply these results to the analysis of treatment assignment rules, and to estimators of cell‐specific parameters that employ shrinkage towards parametric models.     

Design of randomized experiments to measure social interaction effects

We consider randomized experiments with two levels of randomization for measuring social interaction effects. We examine how the randomization should be carried out to estimate the coefficients of interest most precisely.     

Issues of employment portfolios in Japanese retail businesses

Abstract

The employment portfolio of Japanese retail businesses is composed of regular employees and part-time workers. Even though part-time workers are assigned to significant jobs, their wages tend to be lower than those of regular employees. However, the job satisfaction and motivation of part-time workers are not low. This article aims to consider why part-time workers have a positive attitude toward their jobs. Data were collected from part-time workers of retail businesses (n?=?1133). The specific focus is on two groups: part-time workers compared to regular employees and part-time workers compared to other part-time workers. Results showed that the group compared to part-time workers had more positive job attitude than others. From the point of view of social comparison, the job attitude of part-time workers may differ depending on the choice of who they compare themselves against. The implications of the findings and directions for future research are discussed.     

Cost minimization analysis of beta-blocker at the time of CT imaging for suspected of coronary heart disease in Japan

Objectives:

To conduct a cost-minimization analysis of landiolol for CT diagnosis of coronary heart diseases in patients with tachycardia in Japan.

Methods:

A decision-tree model was constructed to analyze costs from the healthcare payer’s perspective. Drug costs and diagnosis costs, computer tomography coronary angiography (CTCA), and coronary angiography (CAG), are adopted to the model. Landiolol is administered only to slow the heart rate to take CT images appropriately. Since some trials proved that there was no difference between landiolol and placebo in terms of efficacy and safety, this study conducted cost-minimization analysis. Of those suspected of coronary heart diseases, 22.5% are thought to be taking beta-blockers. The success rates for CT scanning for landiolol and placebo, derived from domestic trial data, were 81.4% (96/118, 77.8–84.9%) and 54.2% (64/118, 49.7–58.8%). Patients who failed to take a CT image were thought to take CAG. The healthcare cost was derived from a Japanese fee schedule. Costs of landiolol, CT imaging, and CAG are JPY2634 (USD1?=?JPY100, as of November 20, 2013), JPY38,116, and JPY101,322, respectively. The positive rate for CAG, derived from domestic trial data, was 37.1% (33/89, 32.0–42.2%). Various sensitivity analyses, both univariate and probabilistic ones, were conducted.

Results:

In the base case analysis, expected costs per patient for landiolol and placebo were JPY78,956 and JPY82,232, respectively. In budget impact analysis, 81,062 patients are eligible for landiolol and it can save JPY266million for whole patients. Sensitivity analyses suggested the robustness of the results.

Limitations:

This study did not consider any adverse effects in the decision-tree model. This model was developed especially for measuring the cost-saving effect of landiolol, through decreasing the number of patients who require CAG, due to imaging failure.

Conclusions:

Landiolol for CTCA diagnosis in patients suspected of coronary heart disease with tachycardia is thought to be cost saving.