Zusammenfassung der Ressource
Aggregate Demand and Supply
- Aggregate Demand
- C+I+G+(X-M)
- Consumption 60%
- Investment 20%
- Government Spending 25%
- Exports - Imports -5%
- Consumption
- Spending on consumer
goods and services over a
period of time by households
or anyone else
- Influences of
consumer
spending
- Income, Interest Rates,
Confidence, Wealth,
Inflation
- More consumption in
free market
economies where
there is more choice
than in command
economies where
there is no temptation
- Consumption function shows
the relationship between
consumption of households and
determinants of consumption
(main one is disposable income)
- The APC is the ratio of
consumption to income
and is expressed as C/Y.
The APC declines income
increases because the
proportion of income spent
consumption decrease.
- As income rises both APC
and MPC declines, but the
decline in MPC is more than
the decline in APC, as
income falls both APC and
MPC rises but APC rises at a
slower, rate than MPC.
- MPC is useful in
short-period where as APC
is useful in long period. In
the short period there is no
change in MPC and
MPC<APC. In the long
period APC=MPC.
- The MPC is the ratio of
change in consumption to
change in income. MPC=
∆C/∆Y. It is defined as the
rate of change in the
average propensity at
income changes.
- MPC is measured as the
gradient of the consumption
curve. MPC is greater than zero
but less than one because
expenditure must increase with
the increase in income but the
total increase in income is not
consumed - a part of it is saved.
- MPC falls with the fall in income
because as the communities grow
richer, it tends to consume smaller
percentage of each increment to its
income. Because of this tendency as
it moves from left to right.
- Different theories
about consumption
- Keynes
- Consumption planned in
accordance with current
disposable income
- Modigliani
- Consumption is based on what
households think their income
will be over their lifetime
- Friedman
- Households base spending on
their permanent income
(average over their life)
- Saving
- The proportion of a
household's disposable
income which is not spent
over a period of time
- The savings function is the
relationship between the
saving of households and
the factors which determine it
- MPS= ∆S/∆Y
- APS = S/Y
- Y=C+S
- Investment
- Investment is the addition to the capital stock.
Investment can be into physical capital like
factories or machines, or it can be into human
capital like training schemes. The value of
capital will diminish over time (depreciation). Net
investment is positive if gross investment is
greater than depreciation
- main influences of
investment - interest rates/
confidence/ risk/
government and regulations
- Positive net investment will push the PPF
out. Maintenance investment will maintain
the PPF where it is
- Government Spending
- main influences - deliberate
manipulation of economy through fiscal
policy and economic cycle
- Total expenditure by government
and local authorities
- Usually has a multiplier effect
- The gov sets out its plans for spending and taxation in the budget. It is
exogenous - does not vary with the price level. If spending is greater
than tax revenue, the gov runs a budget deficit. The shortfall will have
to be borrowed and accumulates into national debt. On the other
hand, if it is less than tax revenue, there is a budget surplus.
- budget does not have to
balance in the short run
- assess the impact of an
imbalance on the flow of income
- The use of gov expenditure and taxation to
influence the level of AD is called fiscal policy
- Transfers are not included as
AD is REAL economic activity
- Increase
- Change in gov policy
- Increased public
sector wages
- War - spending on defence increases
- Political views, Conservatives spend less, Labour
spend more - different schools of economics
- Increased tax revenue in boom years - more people employed,
more pay taxes, consumption increases so VAT revenue rises,
firms produce more so more excise duties charged
- Decrease
- Increased
unemployment
- Transfer payments
make up a larger
proportion of budget.
Also reduced tax
revenue therefore
lower budget
- Recession/Austerity
measures
- Exports - Imports
- impact on the current account - a
change in the exchange rate/changes
in the state of the world
economy/non-price factors
- EVALUATION
- a change in the exchange rate might have opposite
effects in the short and long run
- a stronger currency makes
exports uncompetitive and imports
cheap
- Decrease AD as X
falls but M rises
- the price elasticity of demand for exports and imports may be
very low meaning that the stronger currency worsens the
current account in the short run
- Exchange Rate
- If interest rates were to rise, there would be more hot
money flowing into the UK, therefore greater demand for
£s so Demand shifts out. Same with confidence -
greater confidence means more investment therefore
demand shifts out. In Greece and Spain, confidence fell,
currency was sold ie money was removed from the
countries' accounts and demand shifted in while supply
shifted out. the exchange rate fell
- Demand of £s comes from exports to
overseas customers and FDI to the UK
- Supply of £s comes from
imports by Britons
- Types of Competition
- Quantity (price)
- Wages, trade tariffs etc
- Quality (non-price)
- Skills, organisation, speed, transportation, customer care
- Ad will increase as a result of decreased
corporation tax, reduced income tax,
increased benefits and increased investment,
but will fall due to a reduction in tariff barriers
because the government wants to deter
imports, so they tax imports and the price of
imports rises. If the tax is reduced, the
imports will be cheaper, our demand will
increase and net trade will decrease as X-M
will be lower and AD will shift inwards
- X-M will increase
- fall in the exchange rate
(depreciation) - exports
become more competitive
while imports become
more expensive
- Improvement in the
quality of domestically
made goods - increases
competitiveness of our
exports
- X-M will decrease
- Incomes in trade partner countries fall
e.g. in the 2008 crash, incomes in Spain
and Ireland fell so demand for UK exports
decreased and this was significant since
50% of our exports are to the EU
- Gov trying to diversify - selling
to the BRICs avoids
dependence on the EU and
also increases exports
- Higher price level in the UK - exports become
less competitive and imports become cheaper.
- Exchange rate
increases (£
strengthens)
- Incomes abroad
increase - export
more
- Incomes in the UK fall,
import less
- High propensity
to import -
significant effect
- We specialise in
services but most of
these aren't traded so
we naturally export less
- Negative for the UK, positive for South
Korea, China and Germany
- Causes of Shifts
- Confidence/Expectations
- Changes in Monetary and Fiscal Policy - There are time lags
between policy changes and the affects on AD.
- Economic events in the international economy e.g. exchange rates/incomes
- Changes in household wealth
- Why does AD slope downwards -
causes of movements along
- Real value of assets/savings increases when
the price level falls, people feel better off and
spend more, so consumption increases
- International price competitiveness is greater when
the price level falls because our exports are cheaper
and imports more expensive so X-M increases
- When the price level falls, the interest rate is reduced.
- Increases Consumption
due to more disposable
income due to lower
monthly repayments
- Increases investment
because the opportunity
cost of reinvesting rather
than saving is lower so
investment is encouraged,
and returns on investments
are likely to be higher
- AD is total spending in the
economy by the 3 main
economic agents (households,
firms and the government) on
real economic activity
- Aggregate Supply
- the factors influencing how much
firms are able and willing to supply
at various prices - costs of
production, level of investment,
availability of factors of production
- Illustrate spare capacity
- Factors that might cause a shift in AS -
changing costs of raw materials/change in
the level of international trade or exchange
rates/technological advances/relative
productivity changes/education and skills
changes/regulation changes