An agreement between the parties on acceptable practices that are not part of a formal agreement. Implicit contracts arise in many social situations and have been proposed to explain labour market institutions. Implicit contracts generally evolve over time and build trust between the parties. For example, it has been proposed that Coca-Cola have an implied contract with its consumers so as not to change the wording of its standard Cola product. An explicit joint agreement is when a company signs a joint venture agreement or partnership with another company. The agreement outlines the financial roles and interests of each company. Sales and acquisitions of real estate generally include formal contracts. Companies sign explicit agreements with lenders to obtain financing. They also ask customers to sign orders to document an agreement to purchase goods or services. The best way to protect your business from lawsuits and unethical practices is to establish formal contracts for all major business transactions. To explain the conundrum of dismissal, models of implicit contracts were developed independently by Martin Baily, Donald Gordon and Costas Azariadis in 1974 and 1975.
   In their models, the company and its workers are not simply buyers and sellers of labour services in a sequential spot market; Instead, employers and workers have a long-term relationship that allows for risk sharing. The most important idea (or assumption) is that employers are risk-neutral, while workers are risk averse. This difference in risk attitude allows both parties to benefit from a long-term working relationship. Under the implied contract, a worker is able to reduce fluctuations in his or her labour income and the employer is able to increase his average earnings. Both parties are therefore doing better than in the spot market. Therefore, the implied contract between an employee and an employer is like insurance used to cover the risk in the spot labour market. Layoffs serve as an insurance premium that workers pay in the long term for the stability of the insurance plan. Companies enter into agreements with business partners, municipalities, customers, employees and shareholders.