Why would an economist choose either the neoclassical perspective or the Keynesian perspective, but not both?

The Neoclassical perspective is based on the idea that market forces, such as supply and demand, will naturally guide the economy towards full employment and stable growth. It assumes that individuals and businesses are rational decision-makers who optimize their choices based on available information. In this perspective, government intervention is usually seen as unnecessary or even harmful, as it can disrupt the proper functioning of the market.

The Keynesian perspective, on the other hand, emphasizes the role of government intervention in managing the economy. According to this perspective, markets do not always lead to full employment and stable growth due to factors such as aggregate demand fluctuations, rigidities in wages and prices, and uncertainty. Thus, government policies, such as fiscal and monetary measures, are needed to stabilize the economy and boost aggregate demand to achieve full employment.

Neoclassical and Keynesian perspectives have different outlooks on the role of the government in the economy, the causes of economic fluctuations, and the relationship between supply and demand. While neoclassical economists believe that markets will self-adjust to achieve equilibrium, Keynesian economists argue that external intervention is necessary.

There are several factors that might lead an economist to choose one perspective over the other. These factors include: 1. Personal belief and conviction: An economist may have a personal preference for one perspective due to their understanding and beliefs about market mechanisms and the role of government. 2. Context and evidence: Depending on economic conditions and historical context, an economist might find one perspective more relevant or appropriate to explain and address economic issues. 3. Intellectual and academic influences: Economists are influenced by their education, mentors, and the academic environment in which they work. These factors can shape their understanding and preferences for different perspectives. 4. Political affiliations or policy preferences: An economist's political views or policy preferences might align more closely with one perspective over the other.

In conclusion, an economist may choose either the neoclassical perspective or the Keynesian perspective, but not both, because these perspectives fundamentally differ in terms of their assumptions, views on the role of government, and explanations of economic fluctuations. The choice between these perspectives is influenced by factors such as personal beliefs, context, intellectual influences, and political affiliations.