Thesis advisor: Robert Murphey / This paper demonstrates that a linear Phillips Curve has neither theoretical nor empirical justification. I first alter the traditional linear model specification to allow for non-linearity between inflation and unemployment. I show that these non-linear models produce greater R2’s than similar linear versions. I provide theoretical justification for the non-linear models and demonstrate why the theoretical reasoning for linear models is flawed. Finally, by introducing the natural rate of unemployment as a separate independent variable, I increase the explanatory power of the model. I allow the natural rate’s marginal effect on inflation to vary with time and suggest a theoretical framework that supports this final model. I conclude that non-linearity and therefore convexity between inflation and unemployment is the correct framework under any time period for Phillips Curve analysis and application. / Thesis (BA) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Economics.