Indiana University-Purdue University Indianapolis (IUPUI) / Linking the new institutionalism to entrepreneurial orientation (EO), my dissertation investigates institutional forces and entrepreneurial forces—two contradicting types of forces—as main effects and moderating effects upon practices and performance of organizations embedded in the institutional duality. The case chosen observes unique hybrid funders that this study collectively calls social investment funders (SIF), which integrate philanthropy and venture capital investment to create and implement a venture philanthropy model for a pursuit of their mission. A theoretical framework is developed to propose regulative and normative pressures from two dominant institutions governing SIFs. Original data collected from 146 organizations are scrutinized by moderated multiple regressions for two empirical studies: Study 1 for effects on SIFs’ venture philanthropy practices, and Study 2 for effects on SIFs’ social and financial performance. Multiple imputations, diagnostic analyses, and several post hoc analyses are also conducted for robustness of data and results from multiple regression analyses. Results from these analyses find that EO and venture capital institutional forces both enhance SIFs’ venture philanthropy practices. A hypothesis postulated for a negative relationship between the nonprofit status and venture philanthropy practices is also supported. Results from moderated regression analyses, along with a subgroup and EO subdimension analyses, confirm a moderating effect between EO and the nonprofit status, i.e., a regulative institutional pressure. A positive relationship is found in EO- financial performance, but not in EO-social performance. While support is lent to hypotheses posited for a social/financial performance relationship with donors’/investors’ demand for social outcomes, and with the management team’s training in business, the overall results remain mixed for Study 2. Nonetheless, this dissertation appears to be the first study to theorize and test EO as a micro-level condition enabling organizations to strategically shape and resist institutional pressures, and it reinforces that organizations’ behavior is not merely a product of their passive conformity to environmental forces, but of the agency, also. As such, this study aims to contribute to scholarly efforts by the “agency camp” of the new institutionalism and EO, answering a call from the leading scholars of both EO (Miller) and the new institutionalism (Oliver).