Report hours worked?

[jdebacker]

Currently, OG-USA reports total "effective" labor supply, L. However, this doesn't directly map to hours worked since workers have varying levels of productivity, which means their effective labor units per unit of labor supply vary.

We should consider reporting an additional measures of labor supply (in addition to L), that represents hours. Perhaps we call this N and N_t= \sum_{s}\sum_{j}n_{j,s,t}\lambda_{j}\omega_{s,t}