《经济学EconomicsforToday3E1》由会员分享，可在线阅读，更多相关《经济学EconomicsforToday3E1（36页珍藏版）》请在金锄头文库上搜索。
1、Chapter 1Introducing the economic way of thinking 3Key conceptsDefining the economic problemDefining the three types of resourcesUnderstanding entrepreneurshipWhat are macro and microeconomics?The purpose of modellingWhat is ceteris paribus?Defining positive and normative economics4The problem of sc
2、arcityScarcity forces us all to make choices as we never have the amount of goods and services we want:individuals: more clothes, etc.governments: more security, etc.Economics aims to explain what occurs as a result of scarcity because wants are forever greater than the available resources.5The econ
3、omic problemScarcity is also called the economic problem Economists aim to show how individuals, groups and society can achieve the most wants given the resources at their disposal.6ResourcesResources are the basic categories of inputs used to produce goods and services.Resources are also called the
4、 factors of production and are split into three main categories:landlabourcapital.7Resources: landAny natural resource provided by nature used in the process of production, for example forests, minerals, wildlife, oil, rivers, lakes and oceans.May be renewable or non-renewable.8Resources: labourThe
5、mental and physical capacity of workers to produce goods and services, for example:farmersnurseslawyers.9EntrepreneurshipEntrepreneurship is a special type of labour: the creative ability of individuals to organise and manage the combination of resources to produce goods and services.10Resources: ca
6、pitalCapital relates to human-made goods that produce goods and services. Capital does not directly satisfy wants but is used to produce the goods and services desired, such as a factory that produce televisions.Money is not included in the economic definition of capital as it is simply a measure of
7、 value placed on goods.11Economics: the study of scarcity and choiceEconomics is the study of how society chooses to allocate its scarce resources to the production of goods and services in order to satisfy unlimited wants.12Two branches of economicsMicroeconomics is the branch of economics that stu
8、dies decision-making by a single individual, household, firm, industry or level of government.Macroeconomics is the branch of economics that studies decision-making for the economy as a whole.13The methodology of economicsEconomists (like other scientists) use scientific method.Scientific method is
9、a step-by-step procedure for solving problems.1Identify the problem.2Develop a model.3Test the model.14The steps in the model-building process15More about modelsA model is a simplified view of reality.It sets out the relationship between variables; causes and effects.A model is valid when it enables
10、 economists to forecast or predict the results of various changes in variables.Example: petrol consumptionIdentifying the problemPetrol consumption has fallen. Why?Developing a modelSelect variables price of petrol, price of cars.Express them verbally, graphically or mathematically.Testing the model
11、Gather data which tells us how well the model estimates or predicts relationships.1617Hazards of the economic way of thinkingThere are two potential problems to be aware of:the ceteris paribus assumptionpossible confusion of association and causation.18Ceteris paribusCeteris (pronounced keteris) par
12、ibus is a Latin phrase which means other things remaining unchanged.Economists use this method as it enables them to see how a change in one variable affects the overall outcome.Imagine: if all the variables change at the same time, how would we know which one caused the change?19Association vs. cau
13、sationWe cannot always assume that when one event follows another, the first caused the second.For example, assume exports from Indonesia rose last month. Two events might be associated:The hole in the ozone layer grew last month.Currency movements reduced the cost to Australians of buying Indonesia
14、n goods.But are they both possible causes?20Why do economists disagree?Economists agree on many things.As in other professions, disagreements occur.One explanation for disagreements is the difference between positive and normative economics.21Positive economicsPositive economics is an analysis limit
15、ed to statements that are verifiable.Positive statements are testable they can be proven true or false.ExamplesAirbags save lives.Smoking is harmful to your health.22Normative economicsNormative economics is an analysis based on value judgements.Normative statements cannot be proven by facts to be t
16、rue or false.They express opinions good, bad, ought to, should.Examples:Every teenager who wants a job should have one.The government should allocate more money to education.Appendix to Chapter 1Applying graphs to economics24Key conceptsWhy use graphs in economics?What is a direct relationship?What
17、is an inverse relationship?What is an independent relationship between two variables?How do we measure the slope of a line?How do graphs show three-variable relationships?25Graphs in economicsGraphs are one of the simplest ways to present, aid and help us to understand relationships and to see econo
18、mic concepts at work.Graphs help economists to understand the relationships that exist between variables.You should learn to draw, describe and interpret them.26A direct relationshipA direct relationship is a positive association between two variables.When one variable increases, the other also incr
19、eases.When one variable decreases, the other also decreases.Note the line on the next slide has a positive slope.27A direct relationship28An inverse relationshipAn inverse relationship is a negative association between two variables.When one variable increases, the other decreases.When one variable
20、decreases, the other increases.Note the line on the next slide has a negative slope.29An inverse relationship30An independent relationshipAn independent relationship is a zero association between two variables.When one variable changes, the other remains unchanged.31An independent relationship32The
21、slope of a straight lineThe ratio of change in the variable on the vertical axis (the rise or fall) to change in the variable on the horizontal axis (the run).Slope = rise/run = vertical axis/horizontal axis = Y/X33The slope of a curveA straight-line relationship is a linear relationship.The slope o
22、f a curve changes from one point on the curve to another.To determine the slope of a curve at any point, draw a tangent to the line at that point, and measure the slope of the tangent.34The slope of a curve35Introducing a third variableHow can a model drawn in two dimensions show the impact of changes in a third variable?We must distinguish between movements and shifts.Movements along a graph show changes in one of the variables on the graphs axes.Shifts show changes in other variables.36A three-variable relationship
