1.0 Introduction Security is an important element of any system design. Entities supported by a system need to securely interact with each other. The problem gets even more complex in the context of a distributed system, where the underling infrastructure of messaging nodes, which we call “brokers,” needs to carry these interactions securely. Furthermore, it is entirely possible that some broke...

Although brokers’ trading is endemic in securities markets, the form of this trading differs between markets. Whereas in some securities markets, brokers may trade with their customers in the same transaction (simultaneous dual trading or SDT), in other markets, brokers are only allowed to trade after their customers in a separate transaction (consecutive dual trading or CDT). We show theoretic...

Seminal models of clientelism assert that parties value brokers for their strong downward ties to voters. Despite its dominance, scholars have not empirically scrutinized key assumptions this theory due the challenges measuring brokers’ network connections. We analyze unique data from three sources—Ghana’s voter register, a handmade catalog local elites, and large-scale survey aspiring party br...

In distributed service oriented ICT environments, where broker components control and delegate the work to appropriate services, the value of information that these brokers use in their mechanisms is found to be prone to the dynamics of the infrastructure. In this paper we describe our research on anticipating brokers that make use of predictive information services. We start with a discussion ...

Grid computing has gone through some generations and as a result only a few widely used middleware architectures remain. Using the tools of these middlewares, various resource brokers have been developed to automate job submission over different grids. Most of the present brokers operate only on a single grid infrastructure, where they have been developed. This taxonomy helps identifying and ca...

This paper presents our work on supporting flexible query evaluation over large distributed, heterogeneous, and autonomous sources. Flexibility means that the query evaluation process can be configured according to application contextspecific, resources constraints and also can interact with its execution environment. Our query evaluation is based on Query Brokers as basic units which allow the...

The value that brokers generate depends on both the quality of their investment recommendations and their clients’ counterfactual portfolios. To identify counterfactual portfolios inside a defined contribution retirement plan, we exploit time-series variation in access to brokers. When brokers are available, the correlations with age, income, and educational attainment suggest that brokers are ...

To measure the causal impact of broker recommendations on their clients portfolios, we exploit time-series variation in access to brokers in a defined contribution retirement plan. When brokers are available, we predict demand for brokers using administrative data on plan participants. The observed correlations with age, income, and educational attainment suggest that brokers are chosen by part...