Cooperation in an Assortative Matching Prisoners Dilemma Experiment with Pro-Social Dummies.

Assortative matching (AM) can be theoretically an effective means to facilitate cooperation. We designed a controlled lab experiment with three treatments on multi-round prisoner's dilemma. With matching based on weighted history (WH) as surrogate for AM, we show that adding pro-social dummies to the WH treatment may significantly improve cooperation, compared to both the random matching and the WH treatment.

Spatial clusters in a global-dependence model.

Spatial data often possess multiple components, such as local clusters and global clustering, and these effects are not easy to be separated. In this study, we propose an approach to deal with the cases where both global clustering and local clusters exist simultaneously. The proposed method is a two-stage approach, estimating the autocorrelation by an EM algorithm and detecting the clusters by a generalized least square method.

A binary-based approach for detecting irregularly shaped clusters.

Background: There are many applications for spatial cluster detection and more detection methods have been proposed in recent years. Most cluster detection methods are efficient in detecting circular (or circular-like) clusters, but the methods which can detect irregular-shaped clusters usually require a lot of computing time.

Methods: We propose a new spatial detection algorithm for lattice data.

Effect of potassium-enriched salt on cardiovascular mortality and medical expenses of elderly men.

Background: The beneficial effects of potassium-enriched salt on blood pressure have been reported in a few short-term trials. The long-term effects of potassium-enriched salt on cardiovascular mortality have not been carefully studied.

Objective: The objective was to examine the effects of potassium-enriched salt on cardiovascular disease (CVD) mortality and medical expenditures in elderly veterans.