What is referred to as the ability of a single economic actor to significantly influence market prices?

The ability of a single economic actor to significantly influence market prices is referred to as market power. This concept is critical in understanding how different entities, such as monopolies or oligopolies, can control the price of goods and services by adjusting supply or demand in a way that impacts the overall market.

Market power arises when a player in the market has enough control over the supply of a product or service to affect its price. For instance, a firm that has a dominant market share can set prices higher than in a competitive market because consumers have fewer alternatives available. This can lead to situations where the firm's objectives may misalign with consumer welfare, resulting in higher prices and reduced output.

In contrast, the other terms do not relate to the capacity of an economic actor to influence market prices. For example, redistributing income deals with how income is shared across a population, externalities refer to the indirect effects of a transaction on third parties, and the standard of living is a measure of wealth and comfort that does not inherently involve market pricing mechanisms. Understanding market power is crucial for analyzing competition and regulatory issues in economics.