Liberal and neoliberal economics are two related but distinct economic philosophies that have had a significant impact on economic policy and theory. Here's an overview of each:

Liberal Economics:

1. Rational Individual Behavior: Liberal economics, also known as classical economics, is founded on the belief that individuals, including producers and consumers, act rationally to maximize their self-interest in the economic system. This concept is central to the idea of an invisible hand proposed by the economist Adam Smith in his work, "The Theory of Moral Sentiments."
2. The Invisible Hand: The invisible hand theory suggests that individual actions motivated by self-interest can lead to the unintended collective benefit and public good in society. In other words, when individuals act in their rational self-interest, the overall economy operates efficiently and secures the welfare of society.
3. Limited Government Intervention: Liberal economics argues for limited government intervention in the economy. The role of the state is primarily to provide essential support services such as maintaining law and order, a functioning judiciary, and essential infrastructure. Beyond these minimal functions, there should be minimal regulation in economic transactions.
4. Criticism and Limitations: While liberal economics offers a compelling argument for the benefits of market-driven self-interest, it has faced criticism for not adequately addressing crises, economic instability, and social inequalities that have arisen in capitalist economies over time. Critics argue that an entirely laissez-faire approach may lead to undesirable outcomes and that some level of government intervention is necessary.

Neoliberal Economics:

1. Market-Centered Approach: Neoliberal economics, often associated with the neoliberalism of the late 20th century, is an economic philosophy that emphasizes the role of markets in promoting economic efficiency and individual liberty. It builds upon the principles of classical liberalism and market-oriented policies.
2. Deregulation and Free Markets: Neoliberalism advocates for the deregulation of markets and the reduction of government intervention in the economy. It supports the removal of trade barriers, privatization of state-owned enterprises, and the encouragement of competition.
3. Emphasis on Individualism: Neoliberalism places a strong emphasis on individualism, personal responsibility, and economic freedom. It argues that market forces, when allowed to operate freely, can drive innovation, economic growth, and prosperity.
4. Critique of State Intervention: Neoliberalism is critical of excessive government intervention in the economy and tends to favour smaller governments and lower taxes. It believes that the private sector, if left unencumbered, can provide better economic outcomes.
5. Globalization: Neoliberalism has been closely associated with globalization, as it promotes free trade, the mobility of capital, and the integration of markets on a global scale.

Neoliberal economics has had a significant influence on economic policies in various countries, particularly during the latter half of the 20th century. It has both proponents who emphasize its potential benefits and critics who argue that it can lead to increased income inequality and economic instability.

In summary, liberal economics and neoliberal economics share the fundamental belief in individual rationality and the role of markets but differ in their approaches to government intervention and regulation, with neoliberalism advocating for more extensive deregulation and market-driven policies.

The central premises of the liberal economic school emphasize individual rationality, limited state regulation, and reliance on market forces. These premises are as follows:

1. Individual Economic Actors are Rational: Liberal economics assumes that individual economic actors, such as producers and consumers, act rationally in their self-interest. They make decisions that maximize their benefits, and this rationality is expected to guide economic activities.
2. State Should Provide Public Goods: According to liberalism, the role of the state should be limited to providing public goods, such as maintaining law and order, a functioning judiciary, and essential infrastructure. The state's primary function is to facilitate economic activity by ensuring a conducive environment for transactions.
3. Laissez-Faire Economy: Liberalism advocates for a laissez-faire economic approach, where market forces are allowed to operate freely with minimal government intervention. The belief is that self-regulating markets, driven by individual self-interest, can lead to efficient economic outcomes.

However, liberalism as a philosophy and economic school has faced several criticisms and challenges:

1. Market Failures: Critics argue that liberalism falls short in addressing market failures, which occur when the free market does not efficiently allocate resources and goods, leading to negative consequences for society. Market failures can result in issues like income inequality and environmental degradation.
2. Distorted Consumer Rationality: Consumer decision-making can be influenced by a lack of reliable information, leading to asymmetric information, where one party to an economic transaction possesses greater knowledge than the other. This can lead to suboptimal decisions and outcomes.

The historical experience of early economic growth based on liberal principles revealed widespread poverty, inequality, and environmental issues. In response, alternative economic schools, such as welfare economics and socialism, emerged to address these shortcomings.

Towards the late 20th century, neoliberalism gained renewed popularity and is often considered a revival of liberal economics. Neoliberalism maintained the core tenets of limited state intervention, globalization, privatization, and deregulation. Key figures like Margaret Thatcher in the UK and policies like the Washington Consensus supported this approach.

Supporters of neoliberalism argue that it encourages individualism, competition, and economic efficiency. However, critics express concerns about inclusivity, growing inequality, neglect of public services, privatization of education and healthcare, and the potential for environmental degradation.

The COVID-19 pandemic in 2020 challenged the neoliberal premise that the state should retreat from social investments and welfare interventions and leave them to the market. Many, including liberals, recognized the importance of the state's role in building human capital and addressing public health and social welfare concerns.