Definitions of direct and indirect effects are given for settings in which individuals are clustered in groups or neighborhoods and in which treatments are administered at the group level. A particular intervention may affect individual outcomes both through its effect on the individual and by...

This paper proposes an empirical method to evaluate decentralized economic development programs with heterogeneous characteristics implemented in different regions or states. The evaluation design developed in the paper is a comparative analysis that operationalizes differences in regional...

Plasma HIV-1 RNA levels and CD4⁺ T cell counts in patients are associated with their progression rates to AIDS. After initiation of highly active antiretroviral therapy, these two variables display time-dependent dynamic changes with particular patterns well described by mathematical functions....