Nonlinear dynamics in a Solow model with delay and non-convex technology

In this paper we propose an extension to the classic Solow model by introducing a non-
concave production function and a time-to-build assumption. The capital accumulation
equation is given by a delay di¤erential equation that has two non-trivial stationary equilib-
ria. By choosing time delay as the bifurcation parameter, we demonstrate that the "high"
stationary solution may lose its stability and a Hopf bifurcation occurs when the delay
passes through critical values. By applying the center manifold theorem and the normal
form theory, we obtain formulas for determining the direction of the Hopf bifurcation and
the stability of bifurcating periodic solutions. In addition, the Lindstedt-Poincaré method
is used to calculate the bifurcated periodic solution, the direction of the bifurcation, and
the stability of the periodic motion resulting from the bifurcation. The Hopf bifurcation is
found to be supercritical. Finally, numerical simulations are given to justify the validity of
the theoretical analysis.