Entrepreneurial Ecosystem Co-Evolution Under Structural Adjustment: A Historical Institutionalist Analysis of Nigerian Enterprise Development Since 1985

This dissertation conducts a historical institutionalist analysis of the co-evolution of Nigeria's entrepreneurial ecosystem with its macroeconomic and political institutional environment from the structural adjustment period of 1985 to the present, generating an original theoretical account of how entrepreneurial ecosystems in developing countries evolve in response to dramatic institutional discontinuities rather than gradual reform. Existing entrepreneurial ecosystem theory assumes relatively stable institutional environments and incremental ecosystem development, but Nigeria's experience includes multiple episodes of dramatic institutional change, including structural adjustment, military governance transitions, banking sector crises, petroleum revenue volatility, and digital economy disruption, each of which has profoundly reshaped the entrepreneurial landscape. The dissertation employs a historical institutionalist methodology combining archival analysis of policy documents, enterprise census data, and business press records with comparative oral history interviews with 35 entrepreneurs who have operated businesses across multiple institutional eras and 20 institutional historians and economists. Path dependence analysis, critical juncture identification, and institutional layering analysis are applied to the longitudinal data. The dissertation's original theoretical contributions are threefold: an Entrepreneurial Ecosystem Path Dependence Model that explains how early enterprise sector configurations create self-reinforcing patterns that persist through subsequent institutional discontinuities; a theory of Critical Entrepreneurship Junctures in which ecosystem direction is determined by specific policy and market events; and a model of Informality as an Ecosystem Adaptation Mechanism, theorising the Nigerian informal sector as an adaptive institutional response to formal ecosystem failure. Keywords: historical institutionalism, entrepreneurial ecosystem, Nigeria, structural adjustment, path dependence.