The authors explore a new framework for evaluating economic development projects. This framework is based on a job-chain approach. Each new job created by an economic development incentive is filled by an employee who leaves behind another job. In turn, that job may be filled by someone who leaves behind their old job, etc. Such job chains end when an unemployedworker, someone not previously in the labor force, or an in-migrant to the labor market takes a vacancy. Job chains are the mechanism for observing and measuring "trickle down". The job trains model developed in this book presents new insights into local economic development evaluation and strategy.