This Major Research Paper (MRP) will examine the consequences of the proposed Growth Plan for the Greater Golden Horseshoe (GGH) on the economic trends of southern Ontario. As a type of regulatory tool, the Growth Plan has inevitable market impacts that must be studied, understood, and mitigated when making policy decisions. Increasing evidence has pointed towards housing affordability, and supply of land and housing types, as two broad market impacts of regulatory tools that fall under the branch of ‘growth management’, ‘urban containment’, and ‘smart growth’. The subject of this MRP is the economic impact of the Growth Plan for the Greater Golden Horseshoe, imposed by the provincial government, and implemented on a municipal level. In 2015, the province initiated its first ten-year review of the 2006 Growth Plan for the GGH. The province released proposed amendments to the Growth Plan in the summer of 2016 following an analysis by a selected panel of experts and input from community consultations. It is anticipated that these proposed amendments will exasperate the widespread affordability issues of the GGH, create a more homogenous built form and building typology, and ignore the diversity of municipalities across the impacted area. A thorough analysis of these adverse effects will be provided along with recommendations on how the province can better balance the environmental, social, and economic goals of the Greater Golden Horseshoe.