Final answer:
The commonly established business structures include sole proprietorship, partnership, corporation, S corporation, and LLC, each with its own advantages and disadvantages, playing a significant role in the market economy.
Step-by-step explanation:
When beginning a business, one must decide what form of business structure to establish. The common business structures include sole proprietorship, partnership, corporation, and S corporation. Another option is a Limited Liability Company (LLC), which is a more recent business structure permitted by state statute. These forms of businesses play a significant role in a free market economy, offering a competitive environment that results in a diverse range of products and services. Each business type comes with its unique set of advantages and disadvantages, and the choice of structure significantly affects factors like taxes, liability, and the ability to grow and evolve through mergers and expansions. Since the larger the profit, the more taxes a business entity might be responsible for, it's important to consider financial implications when choosing the type.