The phrase "poorest groups" refers to people or communities who have very little money or resources compared to others. It means they have the least amount of wealth and are often struggling to meet their basic needs. Full definition
Political and corporate elites are — apparently — susceptible to the temptations and moral hazards of corruption, and — according to psychological and sociological research — more likely to cheat and act unethically than poorer groups in society. (ceassessment.org)
Realistically, this is a pretty poor group of Europa League quarterfinalists; Atleti have to be favorites, though Arsenal know if they can win it, they get CL football next season — and that's the only way it's happening, just like Man Utd last year. (villarrealusa.com)
More specifically with respect to private legal institutions constructed by and for poor groups, Simpson notes that that such institutions (or mechanisms) often lack substantial procedural protections, and rely instead upon cheap methods of enforcement, such as the use of violence and / or the use of volunteers that exert peer pressure. (notjustforlawyers.com)