We solve an optimal growth model in continuous space, continuous and bounded time. The optimizer chooses the optimal trajectories of capital and consumption across space and time by maximizing an objective function with both space and time discounting. We extract the corresponding Pontryagin...

We consider a simple discrete-time version of Lucas (1988). When the speed of human capital accumulation is high (low), the Balanced Growth (Degrowth) Path is the unique optimal solution.