Final answer:
Customers are those outside an organization who use its products or services. The concept of externalities involves third parties affected by transactions they are not part of, while the insider-outsider model delineates between current and new employees of a firm.
Step-by-step explanation:
The term 'customers' generally refers to those who are on the outside of the organization that utilizes the products and/or services of a company. They are not internally involved in the production or service delivery but are the recipients or consumers of the end product. In the context of markets and externalities, customers do not always consider the secondary audiences or third parties who may experience the effects of market exchanges, known as externalities or spillovers.
An example of this would be a scenario where a concert producer builds an outdoor arena close to a residential area. While ticket buyers (the customers) and sellers are pleased with their transaction, nearby residents, who are not part of the exchange, might face negative impacts like noise pollution. This scenario demonstrates the concept of externalities, where third parties bear costs or benefits from a transaction they were not involved in. Similarly, in the insider-outsider model of labor forces, 'insiders' are current employees familiar with the company's operations, whereas 'outsiders' are new or potential hires and do not have the same understanding or influence on the organization.