What Science is a highly stratified social system. Scientific rewards and opportunities accrue disproportionately to a small segment of elite scientists. In science, like in other social systems, hierarchies of status tend to be self-reinforcing. Research demonstrates how scientists that gain small advantages early in their careers are able to translate these advantages into disproportionately greater scientific rewards in the long run. Sociologists have referred to this mechanism as the 'Matthew Effect' in science. In this project, we will examine to what extent this Matthew effect is driven by institutional and country-related status effects. Specifically, we will study how scientists’ scholarly affiliations may shape the reception and uptake of their work among scholarly peers. Why Discussions of how to promote a more open science system have become increasingly salient in science-policy circles. The Open Science movement is taking important steps to improve the transparency, accountability and accessibility of scientific research. However, opening-up science is also about ensuring that new ideas and discoveries attract the attention they deserve, irrespective of who introduces them, or where they are developed. By examining how institutional and country-related status hierarchies may shape scientific careers and influence the reception and uptake of scientific research, this project contributes new insights into this important aspect of the open-science discussion. How In this project, we make an analytical distinction between the "halo effects" and "capacity effects" tied to scholarly affiliations. Here, halo effects refer to how national and institutional status hierarchies may bias the reception of a scientist’s work among scholarly peers. In contrast, capacity effects refer to the capacity of institutions or countries to foster high quality research, for instance through resource accumulation, research infrastructure, and attraction of research talent. Our project combines experimental approaches and analyses of large-scale data on researcher mobility to obtain a closer understanding of both the halo effects and capacity effects at play in science. SSR The policy implications of this project are important, as it will deepen our understanding of the science system’s capacity to make the most of its global talent pool. Our project will contribute fresh insights into longstanding debates on the prevalence of status biases and cumulative advantages tied to geographical and institutional locations. Ultimately, the goal is to inform policy discussions on how to develop more open and reflexive evaluation systems, where researchers’ ideas and discoveries, not their scholarly affiliations, determine future success.