The model, in its present form, is short run in nature. It concerns an economy for which total employment, within-sector productivity and productive capacity are all taken as given. Variations in total output are achieved by workers transferring between two broad sectors that have differing productivity. In considering this economy, discussion has touched on aspects of a steady state and system behavior outside the steady state. It has been supposed, in the event of exogenous shocks, that the broader economy (sector b) drives the adjustment process through its reactions to excess demand or excess supply, with the job-guarantee program (sector j) absorbing or releasing workers as appropriate to maintain total employment at its given level. A tendency for the economy to move toward the steady state has been illustrated with reference to a Keynesian cross diagram (part 2) and a description of the growth behavior of actual output and demand whenever the system is outside the steady state (part 3). Attention now turns to the conditions under which this tendency to a steady state is operative, or, in other words, to the question of dynamic stability.
The model as outlined so far implies particular dynamics. These dynamics are driven by the quantity response of the broader economy (sector b) to mismatches in supply and demand. With the size of the labor force, level of total employment, within-sector productivity and the economy’s productive capacity all taken as exogenously given, the quantity response of sector b requires a change in the sector’s level of employment. The response of sector b induces an inverse response from the job-guarantee sector (sector j), which adjusts as required to maintain full employment at all times. The resulting variations in the composition of employment between higher-productivity sector b and lower-productivity sector j enable the adjustment of total output to total demand.