Why demand changes are manifested as parallel movements of the demand curve

1.First of all, distinguish between demand and demand, demand is the number of goods purchased by households (consumers) in a certain period of time, at a certain level, and the change of commodity ** causes changes in the amount of purchases, which we call the change in demand. It is represented by the movement of points on the curve.

Demand is a group of purchases at a series of ** levels, under the condition that the commodity ** is unchanged, the change in the purchase volume caused by the change of non-** factors (such as income change, etc.) is called the change in demand. It manifests itself as a movement in the demand curve. That is, the demand is not actually a single point, but is made up of an infinite number of points

2.For example, when people's income increases, the demand for a certain commodity increases here if it becomes along the curve, there seems to be no way to express it, because the effect of rising income is not just that the consumer needs more goods at a certain level, but at every level, the consumer needs more goods than the original Therefore, it is made up of an infinite number of points, so it is manifested as a movement of the curve

The premise of demand change is the change of non-** factors, that is, the change of demand ** function, the change of demand curve, which is manifested in the movement of the demand curve on the graph, but not necessarily in parallel.

It is defined in this way, variables other than ** affect the change of demand, which is called demand change, which reflects the movement of the demand curve.

To clarify: it doesn't have to be a parallel movement.

There are five main factors that can make the demand curve move:

1. The product itself. If other factors remain unchanged, the demand for the commodity changes in the opposite direction to its **;

2. Other related commodities. Complementary goods, if two goods can only be used together to satisfy a certain desire of people, then the relationship between these two goods is complementary, and these two commodities are called complementary commodities. If other factors remain constant, in complementary goods, the quantity in demand for one good moves in the opposite direction to the ** of another.

Substitute goods, if both commodities can satisfy a certain common desire of people, then the relationship between these two commodities is a substitution relationship, and these two commodities are called substitute commodities. If other factors remain unchanged, in the substitute commodity, the quantity in demand for one commodity changes in the same direction as that of another commodity;

3. The income level of consumers. All other factors being equal, changes in consumer income can also cause changes in demand for a certain commodity. The demand for normal goods is positively correlated with income; The demand of low-grade merchants is negatively correlated with income;

4. Consumers' expectations for the future. If other factors remain constant, the amount of demand for a certain good is positively correlated with consumer expectations for that good**;

5. Consumer preferences. Consumer preference refers to how much people like a certain product. The amount of demand for a product is positively correlated with the degree of consumer preference for that product.

The demand curve represents the number of goods demanded under each **. The demand curve is a curve that shows the relationship between ** and the quantity of demand, and refers to the table or curve of the amount of goods that buyers are willing to buy at each ** level when other conditions are equal. The demand is not observable.

Demand curves can appear in any shape, and demand curves that conform to the demand theorem can only be sloping down to the right. The demand curve is usually based on the vertical axis (y-axis) and the demand quantity as the horizontal axis (x-axis), in a demand curve that slopes down to the right and is a straight line, the elasticity of demand at the point is equal to one, and the elasticity of the above part of the demand is greater than 1, and the elasticity of the demand of the following part is less than 1.

The market demand curve is a graph that represents the relationship between a product** and the quantity purchased by consumers. Indicates that all else being equal, the number of goods that people are going to buy at a given time depends on **. The higher the market, the less people buy; The lower the market, the more people buy.

1. The change in demand refers to the change in the demand for the commodity caused by the change of the commodity itself when other conditions remain unchanged. It is manifested as a shift in the position of a point on a given demand curve.

2. The change in demand refers to the change in the demand for a commodity caused by changes in other factors under the condition that the commodity remains unchanged.

FYI.

The main differences are:

1. Moving along the demand curve means that the demand has not changed, but the change in demand has led to a change in demand.

2. When the demand curve shifts, the demand changes, even if the demand remains the same, the demand will change, and the common reasons for the change in demand are the change of substitute commodities and the change of complementary commodities.

3. The change in demand refers to the change in the number of goods that consumers are willing and able to buy due to the change of other factors that determine the demand. Graphically, the point moves on a predetermined and non-moving mountain demand curve.

4. The change of demand, that is, the movement of the demand curve, refers to the change in the number of goods that consumers are willing and able to buy due to changes in other factors under the condition that the factors that determine the demand remain unchanged, and other factors here include consumers' income, consumer preferences and related goods. Graphically, it is represented by the movement of the entire demand curve.

The movement of a curve refers to the movement of the curve itself, which is the movement of the curve according to another trajectory (i.e., a function), for example, a curve moving in a straight line will form a surface. The movement of the argument along the curve means that the curve is the trajectory of movement, which can generally refer to the points on the curve.

The difference between moving the demand curve and moving along the demand curve is that the objects are different, the influencing factors are different, and the performance is different.

First, the object is different.

1. The movement of the demand curve: The object of the movement of the demand curve is to analyze the commodity itself.

2. Move along the demand curve: The target object along the demand curve is to analyze the substitute and complementary commodities corresponding to the commodity.

Second, the influencing factors are different.

1. The movement of the demand curve: When the demand curve moves, the demand changes, and even if it remains the same, the demand will change.

2. Move along the demand curve: When moving along the demand curve, the demand does not change, but the change leads to the change in demand.

Third, the performance is different.

1. The movement of the demand curve: The movement of the demand curve is graphically represented as the movement of the entire demand curve.

2. Move along the demand curve: Moving along the demand curve is graphically represented as a point moving on a given and non-moving demand curve.

Answer]: B The movement of the demand curve is not stared at, which means that under the assumption that the commodity is leaking itself, it is caused by changes in other factors, and the option ACD will cause the aggregate demand curve to move parallel to the right.