Lesson1-for-Macro-Economics.docx

**Lesson1: ECONOMIC THINKING** **Understanding Economics and Scarcity** - **Economics** is the study of the trade-offs and choices that we make, given the fact of scarcity. - **Scarcity** means that there are never enough resources to satisfy all human wants. - Every society, a...

**Lesson1: ECONOMIC THINKING** **Understanding Economics and Scarcity** - **Economics** is the study of the trade-offs and choices that we make, given the fact of scarcity. - **Scarcity** means that there are never enough resources to satisfy all human wants. - Every society, at every level, must make choices about how to use its resources. - **Opportunity cost** is what we give up when we choose one thing over another. **Goods and Resources** - **Economic Goods**: goods or services a consumer must pay to obtain; also called scarce goods. - **Free Goods**: goods or services that a consumer can obtain for free because they are abundant relative to the demand. - **Productive Resources**: the inputs used in the production of goods and services to make a profit: land, economic capital, labor, and entrepreneurship; also called "factors of production" **Productive Resources** **Four** **productive resources** also called **factors of production**: - **Land: **any natural resource, including actual land, but also trees, plants, livestock, wind, sun, water, etc. - **Economic capital: **anything that's manufactured in order to be used in the production of goods and services. Note the distinction between financial capital (which is not productive) and economic capital (which is). While money isn't directly productive, the tools and machinery that it buys can be. - **Labor:** any human service---physical or intellectual. Also referred to as *human capital*. - **Entrepreneurship**: the ability of someone (an entrepreneur) to recognize a profit opportunity, organize the other factors of production, and accept risk. **Concept of Opportunity Cost** **Opportunity Cost**: the value of the next best alternative. - **Individual Decisions:** In some cases, recognizing the opportunity cost can alter personal behavior. - **Societal Decisions:** Opportunity cost comes into play with societal decisions. Universal health care would be nice, but the opportunity cost of such a decision would be less housing, environmental protection, or national defense. These trade-offs also arise with government policies.  **Labor, Markets, and Trade** **The Division and Specialization of Labor** - ***division of labor***: the way in which the work required to produce a good or service is divided into tasks performed by different workers. - ***specialization***: when workers or firms focus on particular tasks for which they are well suited within the overall production process. **Why the Division of Labor Increases Production?** - ***economies of scale***: when the average cost of producing each individual unit declines as total output increases. **Trade and Markets** - Specialization only makes sense if workers (and other economic agents such as businesses and nations) can use their income to purchase the other goods and services they need. - Specialization requires trade. - The market allows you to learn a specialized set of skills and then use the pay you receive to buy the goods and services you need or want. - This is how our modern society has evolved into a strong economy. **Using Economic Models** **Economic Model**: a simplified version of reality that allows us to observe, understand, and make predictions about economic behavior. **Economic Models and Math** - Economic models can be represented using words or using mathematics.  - Algebra and graphs are utilized to explain economic models. - When will a firm decide to expand, downsize, or even close? **Using Economic Models: Examples** **Circular Flow Diagram:** a diagram indicating that the economy consists of households and firms interacting in a goods-and-services market and a labor market. - **goods-and-services market **(also called the *product market)*, in which firms sell and households buy.  - **labor market**, in which households sell labor to business firms or other employees. - **real world**, there are many different markets for goods and services and markets for many different types of labor. The circular flow diagram simplifies these distinctions in order to make the picture easier to grasp. **Purpose of Functions** - **Function:** a relationship or expression involving one or more variables. - In economics, functions frequently describe cause and effect. - The variable on the left-hand side is what is being explained ("the effect").  - On the right-hand side is what's doing the explaining ("the causes"). - Economic models tend to express relationships using economic variables, such as: - Budget = money spent on econ books + money spent on music **Solving Simple Equations** **Order of Operations** - When you solve an equation it's important to do each operation in the following order: - Simplify inside parentheses and brackets. - Simplify the exponent. - Multiply and divide from left to right. - Add and subtract from left to right. **Lines** - In this course the most common equation you will see is for a line in graphs: y = b+mx **Understanding Variables** - - **Working with Variables** -  **Creating and Interpreting Graphs** - **intercept**: the point on a graph where a line crosses the vertical axis or horizontal axis. - **slope:** the change in the vertical axis divided by the change in the horizontal axis. - **variable:** a quantity that can assume a range of values. - **x-axis**: the horizontal line on a graph, commonly represents quantity (q) on graphs in economics. - **y-axis**: the vertical line on a graph, commonly represents price (p) on graphs in economics. **Equation for a Line:** y = mx + b - In any equation for a line, *m* is the slope and *b* is the y-intercept. **Interpreting Graphs in Economics** - It is rare for real-world data points to arrange themselves as a perfectly straight line. - It often turns out that a straight line can offer a reasonable approximation of actual data. **Interpreting Slope** **What the Slope Means:** the change in the vertical axis divided by the change in the horizontal axis. - **positive slope** indicates that two variables are positively related; when one variable increases, so does the other, and when one variable decreases, the other also decreases. **What the Slope Means:** the change in the vertical axis divided by the change in the horizontal axis. - **negative slope** indicates that two variables are negatively related; when one variable increases, the other decreases, and when one variable decreases, the other increases. **Interpreting Slope: Slope of Zero** **What the Slope Means:** the change in the vertical axis divided by the change in the horizontal axis. - **Slope of zero** indicates that there is a constant relationship between two variables: when one variable changes, the other does not change.  **Interpreting Slope: Calculating Slope** **Calculating Slope** - The slope of a straight line between two points can be calculated in numerical terms. - To calculate slope, begin by designating one point as the "starting point" and the other point as the "end point" and then calculating the rise over run between these two points. **Calculating Slope** - Graphs of economic relationships are not always straight lines but often nonlinear (curved) lines. - Can interpret nonlinear relationships similarly to the way we interpret linear relationships. - Their slopes can be positive or negative. We can calculate the slopes similarly also, looking at the rise over the run of a segment of a curve. **Types of Graphs: Line** **Line Graphs:** show a relationship between two variables: one measured on the horizontal axis and the other measured on the vertical axis. - Sometimes it's useful to show more than one set of data on the same axes. - The data in the table, below, is displayed in Figure 1, which shows the relationship between two variables: length and median weight for American baby boys and girls during the first three years of life. **Line Graphs:** - The line graph measures length in inches on the horizontal axis and weight in pounds on the vertical axis. For example, point A on the figure shows that a boy who is 28 inches long will have a median weight of about 19 pounds. - One line on the graph shows the length-weight relationship for boys, and the other line shows the relationship for girls. - This kind of graph is widely used by health-care providers to check whether a child's physical development is roughly on track. **Types of Graphs: Pie** **Pie Graphs:** (sometimes called a pie chart) is used to show how an overall total is divided into parts. A circle represents a group as a whole. The slices of this circular "pie" show the relative sizes of subgroups. - These pie graphs show how the U.S. population was divided among children, working-age adults, and the elderly in 1970, 2000, and what is projected for 2030. - In a pie graph, each slice of the pie represents a share of the total, or a percentage. For example, 50% would be half of the pie and 20% would be one-fifth of the pie. - The three pie graphs show that the share of the U.S. population 65 and over is growing. - The pie graphs allow you to get a feel for the relative size of the different age groups from 1970 to 2000 to 2030, without requiring you to slog through the specific numbers and percentages in the table. - Some common examples of how pie graphs are used include dividing the population into groups by age, income level, ethnicity, religion, occupation; dividing different firms into categories by size, industry, number of employees; and dividing up government spending or taxes into its main categories. **Bar Graphs:** uses the height of different bars to compare quantities. - Bar graphs can be subdivided in a way that reveals information similar to that we can get from pie charts. - It is sometimes easier for a reader to run his or her eyes across several bar graphs, comparing the shaded areas, rather than trying to compare several pie graphs. **Bar Graphs:** uses the height of different bars to compare quantities. - The three bar graphs are based on the information from the chart about the U.S. age distribution in 1970, 2000, and 2030. - Graph (a) shows three bars for each year, representing the total number of persons in each age bracket for each year. - Graph (b) shows just one bar for each year, but the different age groups are now shaded inside the bar. - Graph(c), still based on the same data, the vertical axis measures percentages rather than the number of persons. **Types of Graphs: Comparison** How do you know which graph to use for your data? - **Bar graphs** are especially useful when comparing quantities. - For example, if you are studying the populations of different countries, bar graphs can show How do you know which graph to use for your data? - relationships between the population sizes of multiple countries. - Not only can it show these relationships, but it can also show breakdowns of different groups within the population - **Pie graphs** are often better than line graphs at showing how an overall group is divided. - However, if a pie graph has too many slices, it can become difficult to interpret. How do you know which graph to use for your data? - **Line graphs** are often the most effective format for illustrating a relationship between two variables that are both changing. - For example, time-series graphs can show patterns as time changes, like the unemployment rate over time. - Line graphs are widely used in economics to present continuous data about prices, wages, quantities bought and sold, the size of the economy.