It shows the meaning of aggregate demand and aggregate supply. Why aggregate demand curve downward slopping? Show the Short run and Long run Aggregate demand aggregate supply.

2.  Aggregate demand is the total demand for
final goods and services at a given time and
price level. It gives the amounts of goods and
services that will be demanded at all possible
price levels. In other words This is the
demand for the gross domestic product of a
country.

3.  The aggregate demand curve (AD) describes
the total volume of aggregate expenditures in
the economy at different price levels.
 Aggregate demand consists of the amount
households plan to spend on goods (C), plus
planned spending on capital investment, (I) +
government spending, (G) + exports (X)
minus imports (M) from abroad. The standard
equation is:
AD = C + I + G + (X – M)

4.  The aggregate demand curve is plotted with
real output on the horizontal axis and the
price level on the vertical axis.
 the aggregate demand curve, AD, like the
demand curves for individual goods, is
downward sloping, implying that there is an
inverse relationship between the price level
and the quantity demanded of real GDP.

7.  The Price Level and Consumption: The
Wealth Effect
 The Price Level and Investment: The Interest
Rate Effect
 The Price Level and Net Exports: The Net-
export Effect

8.  The aggregate demand curve is drawn under the
assumption that the government holds the supply of
money constant. One can think of the supply of
money as representing the economy's wealth at any
moment in time. As the price level rises, the wealth
of the economy, as measured by the supply of
money, declines in value because the purchasing
power of money falls. As buyers become poorer, they
reduce their purchases of all goods and services. On
the other hand, as the price level falls, the
purchasing power of money rises. Buyers become
wealthier and are able to purchase more goods and
services than before. The wealth effect, therefore,
provides one reason for the inverse relationship
between the price level and real GDP that is reflected
in the downward-sloping demand curve.

9. ◦ A decrease in the price level makes consumers
feel more wealthy, which in turn encourages them
to spend more.
◦ This increase in consumer spending means larger
quantities of goods and services demanded.

10.  The wealth effect occurs because certain
financial assets have returns stated in
nominal dollars. If the price level rises
unexpectedly, the real return on these assets
falls.

11.  suppose that a person purchases a $100 bond
that will pay a 10 percent return, so the
bondholder will receive $110 in one year. The
bondholder forecasts no inflation over the year,
but the inflation rate turns out to be 5 percent.
When the bondholder receives the $110 payment,
the real return is less than the bondholder
expected because the purchasing power of the
$110 is less than it was a year ago. In effect, the
rising price level reduces the bondholder's
wealth. If the value of a person's financial assets
declines, she will reduce consumption, and
Aggregate Demand will decline.

12.  As the price level rises, households and firms
require more money to handle their
transactions. However, the supply of money is
fixed. The increased demand for a fixed
supply of money causes the price of money,
the interest rate, to rise. As the interest rate
rises, spending that is sensitive to rate of
interest will decline. Hence, the interest rate
effect provides another reason for the inverse
relationship between the price level and the
demand for real GDP.

13. ◦ A lower price level reduces the interest rate,
which encourages greater spending on
investment goods.
◦ This increase in investment spending means a
larger quantity of goods and services demanded.

14.  As the domestic price level rises, foreign-made
goods become relatively cheaper so that the
demand for imports increases. However, the rise
in the domestic price level also means that
domestic-made goods are relatively more
expensive to foreign buyers so that the demand
for exports decreases. When exports decrease
and imports increase, net exports (exports -
imports) decrease. Because net exports are a
component of real GDP, the demand for real GDP
declines as net exports decline.

15.  A change in the level of Aggregate Demand that is
caused by a change in the price level is referred to
as a movement along the Aggregate Demand curve.
 The figure titled "Movement Along AD Curve"
illustrates a movement from point A to point B.
 As the price level rises, consumption and net
exports decline because of the wealth and
international trade effects, respectively. The
economy moves along the Aggregate Demand
curve.

17.  A change in any factor other than a change in
the price level that changes the level of
Aggregate Demand results in a shift of the
Aggregate Demand curve
 The figure titled "Shift of Aggregate Demand
Curve" illustrates a rightward shift.
 Factors that Shift the Aggregate Demand
curve include changes in autonomous
consumption, investment, government
expenditures and net exports.

19.  An increase in autonomous consumption :
the portion of consumption that is
independent of disposable income shifts the
Aggregate Demand curve to the right because
for a given price level, the level of Aggregate
Demand is higher than before.

20.  An increase in consumer confidence shifts the
Aggregate Demand curve to the right. An
increase in expected future income also shifts
the Aggregate Demand curve rightward
because consumers believe that their incomes
will increase over time. A decrease in taxes
shifts the Aggregate Demand curve to the
right because for each price level, disposable
income and, hence, consumption are higher
than before.

21.  A change in investment expenditures
It is another factor that shifts the Aggregate
Demand curve. An increase in plant and
equipment expenditures, for example, shifts the
Aggregate Demand curve to the right because
the level of Aggregate Demand is higher at each
price level. Investment could also increase due to
an increase in business confidence or a fall in
interest rates. As we will explore in a later
chapter, the BNR Reserve may lower interest rates
to stimulate investment.

22.  A change in government expenditures
It is a third factor that shifts the Aggregate
Demand curve. A decrease in government
spending to cut back on defense spending at
the end of the Cold War, for example, shifted
the Aggregate Demand curve to the left.

23.  Changes in net exports shift the Aggregate
Demand curve
If net exports rise, the Aggregate Demand curve
shifts to the right. Net exports increase when
there is a weakening of the domestic currency or
when there is an increase in foreign income
relative to domestic income. If the U.S. enters a
recession at the time Canada is in a high growth
mode, U.S. net exports will increase because
Canadians will purchase more U.S. exports but
Americans will purchase fewer Canadian imports.

24.  Meaning:
Aggregate supply (AS) is defined as the total
amount of goods and services produced and
supplied by an economy's firms over a period
of time. The aggregate supply curve shows
the relationship between the aggregate price
level and the quantity of aggregate output
supplied in the economy.

25.  A significant difference exists between the
short-run Aggregate Supply curve and the
long-run Aggregate Supply curve. In the
short run the Aggregate Supply curve is
upward sloping. In the long run the
Aggregate Supply curve is vertical.

26.  The Aggregate Supply curve in the short run
is a time period in which the costs of
production wages, raw materials, energy, and
so on are held constant; only output prices
vary. When prices rise, the level of Aggregate
Supply also rises because firms seek to take
advantage of the profit opportunities. A firm's
profit is the difference between its revenues
and costs over a given time period, say one
year.

27.  Suppose that a firm produces picture frames and
it uses only one input, labor. Each picture frame
requires one labor hour to produce, and wages
are $8 per hour. The firm sells each picture
frame for $10 so the profit per picture frame is
$2 ($10 - $8). If the firm sells 2,000 picture
frames in the first year, its total profit is $4,000
(2,000 x $2). In the second year, the firm
increases the price per picture frame to $11. By
assumption, wages are unchanged at $8 per
hour. The firm's profit per frame produced is $3.
The chance for the firm to increase its profits
provides an incentive for the firm to increase
production.

28.  By producing and selling 2,500 picture
frames in the second year, the firm's profits
rise to $7,500 (2,500 x $3). An increase in
the price level, therefore, leads to a short run
increase in Aggregate Supply. The Figure
labeled "Short Run Aggregate Supply Curve" is
upward sloping, which illustrates the positive
relationship between the price level and
Aggregate Supply.

30.  the long run as a time period in which all
prices and costs are variable. An increase in
the price level will have no impact on
Aggregate Supply in the long run because all
firms' costs (e.g. wages and resource costs)
will rise proportionally with the price level.

31.  the picture frame company increased profits by
increasing the price of picture frames from $10
to $11. Over time, workers adjust their wage
demands upward because goods and services are
more expensive and because good workers are
harder to find as employment rises with the level
of production. Suppose that workers increase
their wage demands to $9 per hour. Now the firm
earns the same $2 profit per frame as it did
before the price level increase and the level of
output returns to 2,000, the same level of
production as in the first year.

32.  In the long run, the Aggregate Supply curve is
vertical as illustrated in the Figure labeled
"Long Run Aggregate Supply Curve." When
resources such as labor and capital are fully
employed, the economy's production is at the
potential level of output, Yp.
 When the economy is on the Long Run
Aggregate Supply curve, GDP is equal to
potential output.

34.  Movements Along AS Curve :
Short-run Aggregate Supply is influenced by a
number of factors. One factor that we have
discussed is a change in the price level. When
the price level changes but resource costs are
held constant, there is a movement along the
Aggregate Supply curve. The figure titled
"Movement Along AS Curve" graphs this
scenario. As the price level rises from PLA to
PLB, Aggregate Supply rises from ASA to ASB.

36.  A change in any factor other than a change in
the price level that changes the level of
Aggregate Supply shifts the Aggregate Supply
curve. Three nonprice factors that shift the
Aggregate Supply curve are changes in
resource costs, technology and inflation
expectations.
 An increase in the cost of a resource will shift
the Aggregate Supply curve to the left.
Resource costs include wages, capital,
energy, and so on

37.  the picture frame firm increased production
when it had a chance to earn higher profits
and reduced production when wages
increased, reducing profits. If resource costs
increase a firm's incentive to produce
decreases as its profits decline. When oil
costs increase, for example, profits decrease
because energy costs increase as utility bills
and fuel expenses rise. For a given price
level, firms respond to rising resource costs
by decreasing Aggregate Supply.

38.  A second factor that shifts the Aggregate Supply
curve is a change in technology. As the Figure
titled "Shift of Aggregate Supply Curve"
illustrates, an increase in technology shifts the
Aggregate Supply curve to the right.
Technological progress influences the economy
in a variety of ways. One channel is the
introduction of entirely new goods and services.
Just a few years ago an on-line textbook was not
possible. Advances in the Internet, however, have
enabled information to be delivered in a new
way. Another way that technology influences the
economy is through quality enhancements of
products

39.  . In contrast to automobiles produced in the
1970s, today's cars are more dependable
thanks to fuel injection systems and other
automated components.
 Newer automobiles are also more fuel-
efficient, and they have air bags and other
safety features that older cars lack.

40.  A third way that technology is integrated into the
economy is through cost-reducing innovations.
The same product can be produced at a lower
cost. First-generation computers used to take up
areas the size of football fields. Today some
hand-held calculators are just as powerful as
those computer but the cost of producing a
calculator is far less than the cost of producing
an old-generation computer. Given the price
level, cost-reducing technological advancements
allow firms to increase production and boost
profits.

41.  Changes in inflation expectations also shift
the Aggregate Supply curve. If workers
believe that inflation will increase in the
future, they will bid up wages to compensate
for the coming inflation. For a given price
level, the increase in wages shifts the
Aggregate Supply curve to the left.

42.  Equilibrium in the macroeconomic sense
occurs when the demand for final goods and
services equals the supply of final goods and
services. A short-run equilibrium, however,
differs from a long-run equilibrium because
in the long run the economy must be
producing at the potential level of output so
that all factors of production are fully
employed.

43.  The short-run equilibrium occurs where the
Aggregate Demand curve crosses the short-
run Aggregate Supply curve. The intersection
of Aggregate Demand and Aggregate Supply
in the figure labeled "Short Run Equilibrium"
determines both the price level and the
equilibrium level of GDP in the economy. The
level of output can be above or below
potential output.

44.  suppose that the economy produces $9
trillion of goods and services in the year 2005
and potential output is $8.5 trillion. As long
as the demand for final goods and services is
also $9 trillion, the economy is at a short-run
equilibrium. Because supply and demand are
equal, firms do not overproduce, which would
lead to an unintended accumulation of
inventories. Nor do firms underproduce,
which would lead to an unintended depletion
of inventories.

46.  The long-run equilibrium can only occur
where the Aggregate Demand curve crosses
the vertical Long Run Aggregate Supply curve
because in the long run, equilibrium output
must equal potential output where all
resources are fully employed. This condition
holds because in the short run, production
input costs are held constant, but in the long
run, input costs can vary

47.  When output is above the potential level of
output, there is pressure on wages to
increase because workers are relatively scarce
and employers bid up wages competing for
the workers. As wages are bid up, the short-
run Aggregate Supply curve shifts to the left
until the equilibrium output is equal to
potential output. This scenario is graphed in
the figure labeled "Long Run Equilibrium."

48.  Conversely, the Aggregate Demand curve
could intersect the short-run Aggregate
Supply curve at a level of output below
potential output. In this scenario,
unemployment would be above the natural
rate of unemployment and there would be
pressure on wages to decline, shifting the
Aggregate Supply curve to the right.

49.  This process would continue until the
Aggregate Demand curve intersected
Aggregate Supply at the potential level of
output. Note that in both short-run and long-
run equilibriums, Aggregate Demand and
Aggregate Supply are equal. The difference
between the two is that the long run
equilibrium requires the additional condition
that output be at the potential level of output.

51.  Suppose the economy is in disequilibrium. Let
us consider first the case in which Aggregate
Demand exceeds Aggregate Supply, or AD >
AS. Demand for goods and services is greater
than the production of goods and services. As
demand outpaces supply, firms see
inventories declining unexpectedly and they
respond by increasing output and prices until
equilibrium is reached.

52.  As the price level rises, aggregate demand
declines due to the wealth and international
trade effects, and aggregate supply rises due
to firms' potential for larger profits. This
scenario is illustrated in the figure titled
"Aggregate Demand Exceeds Aggregate
Supply."

54.  The alternative scenario, illustrated in the figure
titled "Aggregate Supply Exceeds Aggregate
Demand," occurs when the price level is too high
such that Aggregate Demand is less than
Aggregate Supply, or AD < AS. Demand for
goods and services is less than production of
goods and services, and firms see inventories
increasing unexpectedly. They respond by
decreasing production and prices. As the price
level falls, Aggregate Demand increases and
Aggregate Supply decreases. Again, the economy
tends towards equilibrium.

56.  the AS-AD model. The intersection of the
short-run aggregate supply curve, the long-
run aggregate supply curve, and the
aggregate demand curve gives the
equilibrium price level and the equilibrium
level of output.

58.  The primary cause of shifts in the economy is
aggregate demand. Recall that aggregate
demand can be affected by consumers both
domestic and foreign, the Fed, and the
government.
 In general, any expansionary policy shifts the
aggregate demand curve to the right while
any contractionary policy shifts the aggregate
demand curve to the left.

59.  In the long run, though, since long-term
aggregate supply is fixed by the factors of
production, short-term aggregate supply
shifts to the left so that the only effect of a
change in aggregate demand is a change in
the price level.

60.  we begin at point A where short-run
aggregate supply curve 1 meets the long-run
aggregate supply curve and aggregate
demand curve 1. The point where the short-
run aggregate supply curve and the
aggregate demand curve meet is always the
short-run equilibrium. The point where the
long-run aggregate supply curve and the
aggregate demand curve meet is always the
long-run equilibrium. Thus, we are in long-
run equilibrium to begin.

61.  the BNR pursues expansionary monetary
policy. In this case, the aggregate demand
curve shifts to the right from aggregate
demand curve 1 to aggregate demand curve
2. The intersection of short- run aggregate
supply curve 1 and aggregate demand curve
2 has now shifted to the upper right from
point A to point B. At point B, both output
and the price level have increased. This is the
new short-run equilibrium.

62.  But, as we move to the long run, the expected
price level comes into line with the actual
price level as firms, producers, and workers
adjust their expectations. When this occurs,
the short-run aggregate supply curve shifts
along the aggregate demand curve until the
long-run aggregate supply curve, the short-
run aggregate supply curve, and the
aggregate demand curve all intersect.

63.  This is represented by point C and is the new
equilibrium where short-run aggregate
supply curve 2 equals the long-run aggregate
supply curve and aggregate demand curve 2.
Thus, expansionary policy causes output and
the price level to increase in the short run,
but only the price level to increase in the long
run.

65. THANK YOU