Final answer:
Earnings peak during the maturity phase of the business cycle and in mid-life or late middle age for an individual's career, coinciding with stability and experience.
Step-by-step explanation:
Earnings typically peak during the maturity phase of the financial planning cycle. This is the stage in the business cycle where a business has established a solid customer base, operational efficiency, and effective management. During this phase, companies generally enjoy stable earnings and have the ability to pay dividends to investors, as well as reinvest in the business for future growth.
In the context of a person's career and financial planning, earnings usually peak during mid-life or late middle age, which often corresponds with significant experience, expertise, and professional development. This is typically the period before retirement when individuals are at their highest earning potential.