Demand, Supply and Coordination: An Integrated Theory of the Division of Labor

Product demand, supply and internal coordination are all explicitly specified in a model to study how they jointly determine the division of labor (job span). A larger job span means fewer workers are used to cover a production process, which is helpful in coordination and product quality, but not in lowering training cost. Although coordination is at the core, the model shows that, in general, job span is affected by all demand and supply factors. With marginal labor productivity declining, job span is narrower when the market is larger, as Adam Smith believed. It is narrower when coordination technology is better or wage is lower. It is likely narrower when unit training cost or productivity is higher. The results are reversed if labor has increasing marginal productivity. These results are either new or shed new light on previous theories of specialization. They have plausible empirical implications. They show the importance of an integrated approach to the study of job design.