“Principals of Economics”
Economics deals with people and it is a reflection on how they interact with one another. When interacting with others it is based on how ones go about making decisions regarding his or her life. Some of the key points to this article is that it discussed how individuals face trade-offs, the meaning of opportunity cost, how to use marginal reasoning when making decision and how incentives affect people’s behavior.

Economic goods and services are restricted, while the need to use services of these goods and services seem unlimited. There are simply not enough goods and services to please even a small portion of everyone's intake desires. Thus, societies must decide how to use these limited resources and distribute them among different people. This means, to get one thing that we like, we usually have to give up another thing that we also like. Making decision requires trading off one goal against another.

Shortage of economic resources forces people to make tradeoffs. That is, people must always consider how to spend their own limited incomes or time because resources are limited to fulfill their unlimited needs and wants. Tradeoffs or choosing a one thing means giving up something else. When we give up an item, we lose the benefits of its services to us or incur costs to obtain the benefits of the thing we decided to choose. When making decisions it requires comparing the costs and benefits of different courses of action. In economics, the term used to reflect whatever must be given up to obtain some item is called opportunity cost.

In many circumstances, decisions in life are made in small increase or decrease adjustments to the existing plan of action or status quo. Economists call these marginal changes. Imagine a student who is thinking whether he or she should add one more course next semester. They have a rational decision