Theory of the question
Elasticity
1) perfect Assets sostituiti:
Two assets are perfect substitutes if the consumer is disposed to replace a good with the other to a constant test. An example is the red matite ones and the blue matite ones, the indifference curves have constant slope and the usefullness function is u(x1,x2) = ax1 bx2 .
2) perfect Assets complementi:
Two assets are perfect complements if they come consumes to you in fixed proportions jointly : in a sure sense the assets are completed to vicissitude. Their curves of indifference are L. An example is the shoes consumed in proportion 1a1 and also 2 sugar teaspoons in one cup of the. The usefullness function is u(x1,x2) = min{ax1 , bx2 }.
3) Assets neutrali:
A good says neutral if the consumer is indifferent between consuming it and not consuming it. The indifference curves are vertical.
4) Function of usefullness Cobb - Douglas:
u(x1,x2) = x1c x2d
5) Describe the question curve :
Draft of a curve in a position to associating to every price of a good the amount that comes some demanded from the consumer. The anomalous issue is that also being the variable price the independent one, it is found on the formers.
Draft of a curve with negative slope that he is explicable also in terms of decreasing marginal usefullness.
6) Cases in which the curve of the question not negative inclination has one :
to) Assets of lusso it only acquires to you for their exclusive feature
b) there are cases in which the consumers they estimate the quality from the price
7) What is the question function :
To difference of the question curve that only holds account of the relation demanded prezzo/quantità, this function is in a position to expressing the tie between the price, the publicity, the quality of the concurrent products and the amount asked from the consumer.
8) Variable that influences on the curve of the question:
to) Yield
b) Variation of the price
c) Variation of the quality
d) Change of the volume of the publicity
and) advertising Incidence of a product of the competition
f) meteorological conditions
9) Elasticity of the question of the good regarding the price :
We are interested to know like varied the amount acquired from the consumer to varying of the price of the product, the derivative is not but useful for the comparisons therefore the elasticity has been introduced which holds account of the variations percentages.
Elasticity of the question of the good regarding the price
=
10) Elasticity of an arc of the question curve :
Draft of one measure of the medium sensibility to the
variation of the price revealed from one curve of question in limited
drawn its. In short other is not made that to calculate the
elasticity in the combining means point of straight the ends of
intervallo. the Elasticity of an arc of the curve
of question (regarding the price) 
11) punctual Elasticity of the question curve:
Elasticity of the curve of question in a point (regarding
the price) 
12) intercrossed Elasticity:
if and > the 0 2 assets are perfect substitutes in fact if it increases the price of one it increases the amount sold of the other.
if and < the 0 2 assets are perfect complements in fact if it increases the price of one of it the sold amount diminishes and therefore the sold amount also of the other good diminishes inasmuch as they are consumes to you jointly.
13) First theorem of the elasticity:
Given to a segment whichever of the question curve, a variation within the saying limits segment will not have some effect on product PQ > the elasticity of the question along the considered course is exactly equal to the unit, that it happens alone if the question curve is one equilateral hyperbola.
14) According to theorem of the elasticity:
If a question curve has inferior elasticity to the unit (it is inelastic), an increase of the price will increase the expense of the consumer, PQ, and viceversa. If the curve has greater elasticity of the unit (it is elastic), a lessening of the price will increase the expense of the consumer and viceversa.
15) Relation between the elasticity and the curve of question:
A greater elasticity of 1 indicates one strongly sensibility of the question to the price variations, is this the case of the perfect assets substitutes, for which if we change the price of one of the two, the demanded amount of it will drastically diminish to all favor of the good substitute which it has an inferior price.
16) Relation between the elasticity and the revenue:
The elasticity more properly is tied to the marginal
revenue from the 
relation therefore pu² to
observe itself that if the question curve is inelastic (and < the 1) then marginal revenue is
negative and therefore the revenue diminishes to increasing of the
output and siccome the output it is inversely legacy to the prices
then is had that the revenue increases increasing of the prices.
Usefullness
17) Usefullness of a good:
Draft of the subjective benefit that the consumer gains from the possession of the same good.
18) marginal Usefullness of a good:
It is the variation of usefullness associated to a unitary variation of good 1, in short is the derivative of the usefullness function respect to x1 .
19) Like determining the price of a good:
It is equal to the marginal usefullness of the same good.
20) Law of the decreasing marginal usefullness:
It means to describe that how many the more we possess of a good much less we estimate an unit we add them. That it explains also because the question curve is tilted negatively, it will be necessary in fact to reduce the price in order to succeed to sell something of which need is not had.
21) Usefullness orders them:
According to this thought current is not necessary an unit of measure for the usefullness, enough to operate by means of a series of comparisons that gives place to of the indifference maps.
22) Usefullness Neoclassica cardinal:
It stretches to express the usefullness for means of an unit dictates profits and therefore the usefullness comparisons are made in terms of profits. In short an indifference map is taken, is lain down on the plan xy and to every curve of indifference a level is associated on the axis z, whose value per² is not quantizzato.
23) Curve of indifference:
It represents the various baskets of consumption that concur to obtain a sure level of usefullness.
24) marginal Rate substitution:
It represents the test to which the consumer is disposed to replace one of the assets with the other. It is equal to the relationship between the marginal usefullnesses of the 2 assets pertaining to the indifference curves and in particular it coincides with the inclination of the indifference curve.
25) Hypothesis on the necessary psycology of the consumer to the theory of the question:
to) Insaziabilità the consumer prefers to have one q.ta always greater of one or both the assets
b) Transitività
c) Decrease of the marginal rate substitution
26) Property of the indifference curves:
to) an indifference curve that is found more up and more to right it encloses preferred combinations of assets
b) the indifference curves have negative inclination
c) the indifference curves are not never intersected
d) Every curve of indifference is convex regarding the origin.
27) Describe the line of the prices :
It is a straight one that indicates the single amounts of a brace of assets that can be acquired with a sure one to pile of money.
Prezzo_Bene_1 * Quantità_Bene_1 Prezzo_Bene_2 * Quantità_Bene_2 = Amount of money disponibile M
such amount coincides with the purchasing power of the consumer if it is made to correspond one of the assets with the saving that the consumer can allot.
The inclination of the straight one of the prices is equal to the inverse negative of the relationship between the prices of the 2 assets.
28) optimal Combination of purchase:
It is a point given from the intersection between the highest curve than indifference and the line of the prices correspondent to its purchasing power, is characterized from the system between the line of the prices and the condition of ceiling.
29) marginal Condition of equilibrium of the consumer:
It is a condition that is extracted from the optimal
combination of purchase and says that the relationship between the
prices of the 2 assets is equal to the relationship of their
usefullnesses marginali 
=
marginal rate sostituzione .
30) Describe the curve of Engel:
It is the curve that to varying of the yield joins all the optimal baskets, also is said the yield-consumption curve.
31) Good normale:
It is a good whose question increases increasing of the yield and diminishes to its to diminish.
32) inferior Good:
It is a good of inferior quality whose question falls when it improves the position financial institution of the consumer, and produced more attractive is replaced to it. It is characterized from the fact that as a result of a variation of the price, the substitution effect is discorde with the effect of yield but in greater module.
33) Good of Giffen:
Draft of an inferior good but that it differs from they because the yield effect prevails on the substitution effect, determining itself with that that even if diminishes its price, will sell one greater amount of the other good.
34) Like determining the nature of a bene:
If of it must vary the price and estimate the yield and substitution effect, the following cases are introduced :
to) the good it is normal if the effect of substitution and the effect of yield are agree.
b) the good is inferior if the effect of substitution and the effect of yield are disagree.
c) the good beyond to being inferior is of Giffen if the yield effect prevails on the substitution effect.
35) Describe the curve of offerta:
How much is an indicating curve the variations of the price of one of the assets affects both the assets, is obtained making to diminish the price of the good brought back on the abscissas concurring therefore with the curve of the prices to lose heart itself, then combines the points of equilibrium ceiling.
36) Identity of Slutsky:
It asserts that to continuation of the variation of the price of one of the assets, one will be had variation of the amount sold equal to the sum of the effect of yield and the effect of substitution. In formulas : Dx = Dxsubstitution Dxyield
37) Describe the effect of sostituzione:
If the price of good 1 diminishes, the purchases of good 1 sostituiranno to the purchases of good 2 because the first one is relatively more convenient, in the cares of the price, of how much it was not to the beginning. It is equal to the difference between the amount of the good 1 present in the optimal basket straight correspondent to ruotata and the amount of the good 1 present in the antecedent optimal basket the variation of the price.
38) Describe the effect of reddito:
If the price of good 1 diminishes, the consumer will have to disposition a greater yield that the assets riverserà in purchases of both. It is equal to the difference between the amount of the good 1 present in the straight optimal basket of roto - traslata and the amount of the good 1 present in the ruotata optimal basket of the straight one.
39) Effect of the lessening of the price of a good for one brace of perfect assets complementi:
The curves of indifference in this case are of the L therefore a spin regarding the point of optimal, will not move optimal the same one, therefore the substitution effect is null in this case. Of the rest it is intuitivo because if it diminishes the price of does not have sense to replace it with the other inasmuch as the two assets must be consume to you jointly.
40) Effect of the lessening of the price of a good for one brace of perfect assets sostituti:
The only effect is a substitution effect, in how much the consumer will choose hour the good well that has the smaller price, not buying some having unit del the greater price.
41) Principle of the preferences rivelate:
It is (x1 , x2) the chosen basket in correspondence of prices (p1 , p2) and (y1 , y2) a such other open baskets that to parity of 2 price havep1x 1 p2x 2 ³p1y 1 py2 then if it is true that the consumer chooses the preferred basket between that can acquire, must essere (x1 , x2) < (y1 , y2).
42) Index of the amounts of Paasche:
It concurs to estimate if the situation of the consumer is better to the time t of how much were not to the time base b,
the prices are taken therefore like reference to the time t.
for such index we can use the preferences revealed in how
much the prices to the numerator and to the denominator they are the
same ones. As an example if the index is greater of 1 it has 
and therefore the economic position of the
consumer to the time t is better than how much it was not to the time
base.
43) Index of the amounts of Laspeyres:
It concurs to estimate if the situation of the consumer is better to the time base b of how much will not be to the time t,
the prices are taken therefore like reference to the time base b.
if such index is smaller of 1, based on the preferences revealed we know that the situation of the consumer to the time b is better than how much it will not be to the time t.
44) Price index of Paasche:
It concurs to estimate if the situation of the consumer is better to the time t of how much were not to the time base b,
the amounts are taken therefore like reference to the time t.
Since in this case the prices vary, pu² not to apply the
criterion of the revealed preferences but will have to be confronted
this index with the index of the variation of the expense 
total.
45) Price index of Laspeyres:
It concurs to estimate if the situation of the consumer is better to the time base b of how much will not be to the time t,
the amounts are taken therefore like reference to the time base b.
46) Surplus of the consumatore:
It is the area under the question curve, if a market price is settled down then the surplus clearly is the part of downstairs to the question curve and that it has a advanced price at the price of market. If the varied market price then the surplus variation is sum of two areas :
R is the lessening of surplus due to the increase of the price
T is the lessening of surplus due to the lessening of the buyable amount.
47) Surplus of the produttore:
It is the area to of over of the question curve, if a market price is settled down then the surplus clearly is the part of advanced plan to the offer curve and that it has an inferior price at the price of market. If the varied market price then the surplus variation is sum of two areas :
R is the increase of surplus due to the increase of the price
T is the surplus increase due to the fact that sells one advanced amount.
48) Ricavo:
He is equal to the product of the price of a good for the sold amount.
49) Revenue marginale:
.
50) Market concorrenziale:
It is a market in which every agent considers the market price to outside of just the control.
51) Paretiana Efficiency:
An economic situation says Pareto - efficient if some way does not exist to increase the satisfaction of someone without to reduce the satisfaction of qualcun other.