The Short-run Macroeconomic Equilibrium

A very simplified Keynesian model is used to show the short-run macroeconomic equilibrium. For example, the rate of interest is fixed to simplify the model by keeping constant money in the economy. It is also assumed that production and employment depend on the amount of spending. In that we mean that if people buy more then firms will produce more, providing that they have the spare capacity available. The basic formula we use is that the level of National Income is equal to the domestic consumption plus the three withdrawals from the circular flow of income. Or, in shortened terms: Y = Cd + W. In this model, aggregate demand is actually known as aggregate expenditure (E) and relies on the amount of domestic consumption and the injections into the circular flow of income (J). Also written as AD = E = Cd + J. We reach a point of equilibrium when withdrawals equal injections and at this same point National Income will equal aggregate expenditure. If injections were to be higher than withdrawals then National Income would rise and the withdrawals would rise until withdrawals is once again equal to injections. Now enter the 45 degree line.

The 45 degree line shows the relationship between National Income and consumption, withdrawals and injections. Consumption and withdrawals are endogenous - their value is determined by the model. However injections are exogenous, meaning their value is determined independently of the model.

At ever point on the 45 degree line (Y), the items on each axis equal each other. The C line is consumption. It differs from Cd because it doesn't contain taxes and export spending. Consumption is a function of National Income: C = f(Y). As National Income rises, so does consumption - hence the upwards slope. It crosses the 45 degree line because poorer people may be required to spending above their earnings to survive where as richer people spend less than they earn, therefore at the end of the line it is below the Y line. The slope is given by the marginal propensity to consume - the proportion of any increase in National Income that goes on consumption. It is the change in consumption divided by the change in National Income. 

Consumption is determined by a whole bunch of different things: 

• Taxes
• Expected future incomes
• Expected future prices
• Consumer confidence
• Household wealth 
• Attitudes of the lenders
• Age of 'durables'
• Distribution of income

Any changes in these cause a shift in the consumption function whereas a change in National Income causes a movement along the consumption function. 

Now onto the withdrawals. The amount saved depends on the marginal propensity to save (mps). The proportion of an increase in National Income that is saved. Mps = Change in savings / Change in N.I. Taxes is pretty much the same - it depends on the marginal propensity to tax (mpt), or changes in tax / changes in N.I. It tends to rise as National Income rises because income tax is progressive. Finally imports - depending on the marginal propensity to import. Or, mpm = change in imports / change in National Income. 

Total withdrawals will look something like this: 

Injections now and we'll start with investment. It is determined by the following things: Consumer demand, expectations, interest rate, availability of finance and cost/efficiency of capital equipment. Replacing new equipment will rely on National Income. Government spending is independent of National Income in the short term, Exports is also classed as independent on National Income to keep the model simpler.  

That's it for the background on the theory. Next we'll be moving on to how National Income is determined from all of this. Stay tuned.

Sam. 

The Circular Flow Of Income

*I'd like to start by wishing everyone a happy new year! I hope you all had a good time over the festive period and are getting back into the swing of things as life returns to normal. I've had a great 4 week break and am now back studying, which mean the blog will be starting again on a consistent basis until Easter!*

Today's focus will be on the circular flow of income. I'm aware this has already been discussed but like I mentioned in a previous post I do plan on going over things again in a little more depth. The best way to learn about the circular flow of income is to actually see the flow graphically:

I'll now break the flow down into it's different sections, starting with the inner flow. The inner flow consists of the factors payments going from the firm to the households and payments for goods (consumption) flowing in the opposite direction. Firms pay money to households in the form of wages, interest and rent in return for the services of these factors of production. On the other side, households pay money to firms when they consume the firms goods and services. Note we're talking only about domestic firms and domestic households here.

In a scenario where all money was spent then that would complete the flow. However, in reality, not all money is spent. This is where the concepts of injections and withdrawals from the flow come in. Withdrawals are exactly what they sound like: money being taken out of the flow. It comes in three main forms. Firstly, savings. When money is deposited in banks or other financial institutions for the future that money has been withdrawn from the flow. Taxation is another withdrawal. Income tax and national insurance comes out of a households income whereas VAT comes out of a households consumption. Receiving benefits from the government is essentially a 'negative tax'. It's a tax that is flowing in the opposite direction. Therefore the total withdrawal in the form of net taxes is total taxation minus benefit payments. The final withdrawal is import spending. This is money that has left the flow of income because it is spent on goods and services abroad.

Injections, defined as additional money flowing into the economy, also comes in three forms. Firstly: investment. Investment is money that firms spend after gaining it through financial institutions. Secondly there is government spending. This includes such things as spending on roads, hospitals, schools and the like. It does not include state benefits, that is important to note! Finally, the other injection is export spending. Money that has come from people abroad buying our domestic goods and services.

There is a slight relationship between the withdrawals and injections into the circular flow of income. For example, suppose more money is saved (withdrawal) then more money will be available for banks to lend out to firms for investment (injection). The higher taxation is (withdrawal), the more like the government are to increase spending (injection). However, we must remember that these choices are made by different people. The choice to save and the choice to invest are made by two completely different, independent parties and therefore each will have their own agenda. Due to this we can say that injections may not equal withdrawals, however they could.

The final point I'd like to discuss here is equilibrium in the circular flow if income. Like most things in economics, market forces are able to bring the circular flow to equilibrium. I'll give an example. Suppose that injections exceed withdrawals. This may be because investment has rise, but irrespective of the reason due to  this national income will rise (because of more money circulating). A higher national income means that people can consume more, but as well as this people can also save more, pay more taxes and buy more imports. Therefore withdrawals will rise, and continue to rise up to a point where it is equal to injections. This is when equilibrium has been reached and national income will remain constant until another change occurs.

Thank you for reading guys and girls. Contact me if you have any questions or feedback, have a good day/night! Sam.

Principles of Economics - Perfect Competition

Perfect Competition is a market structure that follows these assumptions:

• Firms are price takers - each firm has no impact on the price in the market, they take the price the market forces set.
• Freedom of entry into the market - there are low barriers to entry so anyone could potentially set up in this market.
• Firms produce identical products - the taxi market for example, each taxi firm offers an identical product.
• Producers and consumers have perfect knowledge - both producers and consumers know everything there is to be known about the market.

However, few, if any, industries are actually perfectly competitive.

In the short run, the number of firms is fixed. In the long run, if supernormal profits are being made then new firms will enter the industry. If losses are being made, firms will leave the industry. 

Short run equilibrium of the firm:

This is what the market looks like in the short run in perfect competition. The price is Pe, and is set by the demand and supply forces. It is horizontal because firms are price takers. Due to price being constant, the red dotted line is also the average revenue, the marginal revenue and the demand for the firm as they're all the same. Qe is the amount produced by the firm because this is the amount at which profits are maximised (MC = MR). There is slight profit being made because the average revenue is higher than the average cost at the production point.

This is where the long run can be introduced. In the long run, firms see these profits being made and enter the industry. These means the industry supply increases, shifting the supply curve to the right on the left hand diagram above. Price falls, which means each firms demand falls until the point it is equal to the average cost. At this point, firms break even and make no profit. Firms will stop entering the industry now.

As far as the public interest goes with perfect competition, it has its benefits and drawbacks. The benefits are as follows:

• Firms produce at the least cost output.
• Firms that are inefficient will be forced out.
• Prices are minimised.
• Consumers determine what and how much is produced.

The drawbacks are:

• There us very little incentive to invest in new technology.
• Goods are all the same, lack of variety for consumers.

That ties up this post about perfect competition. Thank you for reading, keep checking back and sharing. Have a good day!

Sam.

Common Agricultural Policy Part 3 - Buffer Stocks

A tool at the EU's disposal within the CAP is buffer stocks. They can use these to either stabilise the prices of farm produce or to stabilise farmers income.

First case we'll analyse is the case of buffer stocks being used to stabilise prices of farm produce.

We have a market for a crop here, Q1 and P1 being the equilibrium quantity and price respectively. Lets assume one year there is a good harvest, supply increases to S1. We notice that this would create a fall in price, however as the policy is aiming to stabilise prices this isn't what we want. So, in order for this supply increase to come with stable prices, the governments need to buy up the difference between Q1 and Q2 and put them into buffer stocks. This means, the quantity available to the public is the original level of Q1, and therefore price won't change. 

Alternatively, if there is a bad harvest and supply falls to S2, a price rise would occur. The governments would have to intervene here and sell the difference between Q1 and Q3 to the market, releasing them from buffer stocks so the quantity available is the same and therefore the price remains stable. 

The areas on the diagram represent a few different things. Area a is an income that the farmers are guaranteed, even in the worst times. Area a + b is the normal income for a farmer, assuming that the harvest is a normal one. Area c is extra income the farmer would earn given a good harvest. Notice this policy of stabilising the farming prices has created more fluctuation in the farmers incomes, something the CAP aims to eradicate. Controversial.

Now, onto how buffer stocks can be used to stabilise a farms income. This involves using the elasticity formula. If elasticity of the good equals to 1, then the percentage increase in quantity is the same as the percentage fall in price. Therefore, if these are the same then the income of the farmer will remain constant. 

This diagram shows the principle of stabilising a farmers income using buffer stocks. We have an initial equilibrium of P1 and Q1, and supply increases because of a good harvest. This essentially means that a new equilibrium will be formed at P2 and Q2. However, at this point the farmers income has changed because demand doesn't have unitary elasticity. Therefore, the government needs to intervene. Using the curve above, we can see where the price and quantity should be for farmers income to remain stable: P2' and Q2'. So, what the government needs to do is buy up the difference between Q2 and Q2' and put them into buffer stocks. This means that the quantity now available will mean that price is at P2' and therefore farmers income will be stable. We can see this visually, the farmer has lost area c in terms of income due to the price fall,but gained area a + b due to the increase in quantity. These areas should be identical and therefore the farmers income has remained constant. 

This concept also works the other way if supply were to fall. Just in this case the governments would be releasing from the buffer stocks in order to regulate the price and quantity so that the farmers income remains stable. 

Buffer stocks is one method the government has to try and stop price fluctuations or income fluctuations, however it cannot be used to control both at the same time. Next up will be the use of subsidies for the same reasons. 

Sam.

Common Agricultural Policy Part 1 - Price Fluctuations

The Common Agricultural Policy is a massive deal in Europe and the European Union. It's a very expensive policy that started out back in 1962 as a simple price support policy. It has two key objectives: to stabilise prices and to provide income support for social reasons. If you look at the distribution of farms across Europe, it is clear to see why this is needed. The biggest 7% of farmers own roughly half the land, whilst the smallest 50% of farmers own only 7% of land. This is a massive inequality and could lead to monopoly powers, outlandish prices and other such problems if it went unregulated.

We'll first look at a few of the characteristics of the agricultural industry. There are many producers, all are price takes. There are also many consumers, all of which are also price takers. There is generally freedom of entry and exit into the industry. It's about as close to perfect competition as you could get in a realistic scenario. Governments need to intervene for many reasons:

• To reduce price fluctuations.
• Raise farm incomes.
• Protect rural communities.
• To encourage greater self-sufficiency.

Firstly, I'm going to focus on the price fluctuations. In the short term they are caused by instability and the fluctuations in the harvest (good or bad!). Let's assume that the demand for a crop were to rise one year, which would cause a shift to the right of the demand curve. Supply in the short term obviously cannot react to this because supply is fixed each year depending on what is planted. This demand rise will cause a rise from price P1 to P2. This is all shown on the diagram below.

The farmers observe this rise in price and then next year they increase their supply to the market. At P2 the farmers decide that Q2 is the correct quantity to supply to the market. However, at this amount supplied, demand is outstripped and therefore price must fall to P3. The year after, at price P3 a different amount is supplied by the farmers, but at this supply more is demanded and therefore price rises again. This will continue, as shown on the diagram below we can see that the market is slowly spiralling towards a point of equilibrium at which both consumers and producers would be happy. 

We call this concept a stable cobweb. This price fluctuations and changes are supply are making the market more and more stable as over time the fluctuations get smaller until equilibrium is finally met. In this case, the government wouldn't need to intervene in the agricultural industry. However, there is the opposite case. An unstable cobweb could appear. The case of this occurs when the supply of the crop is very elastic. Diagramatically, the supply curve will be much flatter. The same instance as above will occur, demand increases causing a price rise as supply is fixed. In the second term supply is increased due to this new price, but there is oversupply and price has to fall... and so on and so forth. Except, when the supply curve is elastic this doesn't spiral towards equilibrium, it spirals away from it as can be seen in the diagram below.

This shows one of the cases in which the government would need to intervene in the agricultural industry, hence the Common Agricultural Policy. The price fluctuations in this unstable cobweb would keep getting worse and worse if left to market forces. 

Next we'll move on too supply side shocks. This is when supply is affected, either for good or for bad, and therefore the supply of the crop isn't as expected. Once again, diagrams are an easier way of showing this. The first case will be a bad harvest, where supply of the crop is less than what was expected. The diagram below shows this. Supply of the crop has fallen from the expected level of Qe to the actual level of Qa. The area labelled 'b' is income that the farmer has lost, the area labelled 'c' is income gained from this supply side shock. The expected income for the farmer was area 'ab', but the actual income of the farmer is now area 'ac'. If area c is greater than area b then the farmer has gained, otherwise the farmer has lost out due to the bad harvest. Generally, the more inelastic demand is, the greater are 'c' is and therefore the more likely the farmer will benefit. 

I'll quickly go through the other supply side shock as well. As you can guess, this is when there is a better harvest than expected. This causes a shift to the right of actual supply from Qe to Qa. A fall in price is seen from Pe to Pa and once again the farmers income may be affected. Area 'c' is the income gain, area 'b' is the income loss and area 'a' is the income that has stayed constant. If area 'b' is bigger than area 'c' then the farmer has lost out. 

What we have achieved in this blog post is the causes of the fluctuations in prices of harvested goods. This is one of the things the Common Agricultural Policy aims to stop, as stable prices is an aim. In the next post we'll look at what is causing the decline of farmers income and then we'll move on to look at how the government intervenes in this policy to correct these issues.

Stay tuned guys, enjoy!

Sam.

Principles of Economics: Demand (Microeconomics)

*Disclaimer: I'm fully aware of the fact that I've already written a post on demand. However, I've decided to cover it again now I know more on the subject and can give a better coverage.*

Basically, I'm back to cover a very basic principle of microeconomics: Demand. Demand refers to the amount consumers can and are able to purchase of a good or service, 'can and able' being a very important part. Note that a consumers want for a good should not be included in demand. I'm sure everyone wants a flashy sports car on their drive yet the true demand of that good will be very small. Glad we got that out of the way. The demand of a good in a market plays a pivotal role in determining the price. For this, demand must interact with supply and the point at which they meet can be called the 'market output' or the 'equilibrium output'. This is displayed on a graph which I'll do a post about in a few days. The price at this 'equilibrium output' is called the 'market price' or the 'equilibrium price' which is essentially the price consumers have to pay for the good and the price suppliers are selling at.

It's important for me to point out here also that when looking at demand we assume that we're operating in a market of perfect competition. This basically means that in the market there are an abundance of consumers and producers and therefore they have no control over prices. We call them price takers. The size of each producer is too small and there is too much competition from other firms that it would be impossible for them to raise prices and still make sales. Perfect competition is the closest theoretical example to most real-world markets and therefore we use it in our examples.

Let's now look at the relationship between the demand and the price of a good or service. The law of demand is as such: 'When the price of a good rises, the quantity demanded will fall'. This occurs for two reasons:

1. The good/service will cost more than substitute goods. Other similar products will be comparatively cheaper and therefore demand for the good will fall as consumers start to purchase the substitute. For example, a Playstation 3 could be said to be a substitute good for an Xbox 360. Therefore, if the price of the Xbox 360 were to rise then the demand for it would fall as consumers move over to purchase the comparatively cheaper Playstation 3. This is called the 'substitution effect' of a rise in price.
2. People will feel poorer. A rise in the price of a good means people will effectively be able to afford less of the good which makes them seem less well-off, or poorer. This is known as the 'income effect' of a price rise. 

Obviously it occurs the other way also; if the price of a good falls then the quantity demanded will rise. We'll consider the following example, theoretical figures for the monthly coffee demand:

Now, if we were to plot the demand curve for this data it would look something like this:

A typical demand curve would look like this, if real data is being used. The curve you can see slopes downwards from left to right, also called a negative slope, as when the price falls the quantity demanded rises. In most cases, however, real figures aren't used, it's just theoretical. In these cases the demand curve will just be a straight line sloping down from left to right. Remember that we still use the term 'curve' when the line is straight. 

Apart from the price of a good, the demand for a product is also determined by other factors. These are as follows:

• Tastes - The more desirable a good the more it will be demanded and vice versa. This is often affected by advertisements, fashions and what other consumers are purchasing. 
• Quantity and Price of Substitute Goods - If a substitute good has a higher price then demand for the good in question will be higher. If the substitute good has a lower price then the demand will be lower for the initial good.
• Quantity and Price of Complimentary Goods - This works in the opposite way to above. Complimentary goods are products that are consumed together, examples would be cars and petrol or DVD players and the actual DVDs. If the complimentary good's price rises you can expect the demand for the good in question to fall and vice versa. 
• Income - This one is fairly obvious. As people's incomes rise, so does their spending power and therefore demand for 'normal' goods will rise. With this, demand for 'inferior' goods will fall. When we say 'inferior' goods we are talking about things such as supermarket own brand foods. 
• Distribution of Incomes - This determinant is a little more ambiguous. If wealth was re-distributed from the rich to the poor, then demand for luxury items would rise as the poorer people would be able to buy these goods for the first times. It works in the opposite way too, if the poor in society get poorer then the demand for 'normal' goods will fall as the demand for 'inferior' goods should rise. 
• Expectations - Last but not least, people's expectations. Everyone speculates, and if the speculation is that the price of a good is set to rise in the near future then we can expect demand to rise in the short term. If the price is expected to fall we'd expect demand to fall as people hold out until the lower price arrives. 

When we put together a demand curve, we do it assuming that all other things are remaining equal and this is known as ceteris paribus. Nothing but the price changes and when the price changes it results in a movement along the curve. A movement along the curve is different to a shift of the curve, which is very important to remember. When any other determinant of demand changes the curves will shift. A movement along means the demand curve remains the same but the demand just moves to a different point on that curve. A shift means a new demand curve, where at each price a different amount is demanded. 

This is the same demand curve we used earlier, but here we can see that the demand curve has shifted. At each price a different amount of coffee is being demanded. This occurs when a non-price determinant of demand changes. That's probably the hardest basic principle of demand to grasp, but here it is summed up:

• A change in price results in a movement along the demand curve.
• A change in a non-price determinant results in a shift  of the demand curve.

If the change in the determinant of demand causes a rise in demand then the demand curve will shift to the right. If the change in the determinant causes a fall in demand then the demand curve will shift to the left.
The proper names for these two principles are as follows:

• A shift in the demand curve is called a change in demand.
• A movement along  the demand curve is called a change in the quantity demanded.

And that is pretty much that, the principles of demand. The hardest part here is probably differentiating between a movement a long and a shift in the demand curve, however you can pick it up rather quickly. Feel free to comment if you feel i missed something out or something is incorrect. Thanks for reading!

Sam.

Externalities (Microeconomics)

An externality, in the economic world, occurs when people not directly involved in a decision are affected by it. Some examples of this are fishermen may not be able to fish in a river if someone has contaminated it with rubbish or a new hospital being built will benefit all people in the local area. The term given to those not directly involved in the decision is third party. The third parties in the two examples I've given are the fishermen and the people in the local area.

Linked in with the externalities theory are the costs and benefits that come about from someones decision. The three types are private, external and social. Private costs/benefits are the costs and benefits to the person actually making the decision. Say i decided to pave over my front garden, the private cost would be me losing garden space but the private benefit would be extra parking space. External costs/benefits are the costs and benefits of a decision that someone makes that fall onto the third party. Continuing my example, the external cost of me paving my garden would be the street wouldn't like as nice to the neighbours and passers-by. The external benefits would be a clearer road for the neighbours to drive down because i could then park my car on the new paved area rather than in the street. Finally, the social costs/benefits are the total costs and benefits to society as a whole of the decision. The social cost equals the private costs plus the external costs.

External costs = Social costs - Private costs.
External benefits = Social benefits - Private benefits.

When the social cost is higher than the private cost it means there are external costs in play, these are known as negative externalities. Binge drinking, chewing gum and fly tipping all have negative externalities. The situation of a negative externality can be illustrated on a diagram...

The diagram represents our negative externality. The current equilibrium point is PQ, at this price we are at supply curve 'Supply' but this is only taking into account the private costs of the good. If the external costs are taken into account then the supply curve should shift leftwards to 'Supply 1'. This would raise the price to pay for the extra external costs, as well as lower the supply. The problem with negative externalities is that there is over-production of Q-Q1 and price is lower than it should be. Too many scarce resources are being used, so there is market failure.

Positive externalities work in the same way, this is when the social benefit of a decision is higher than the private benefit.Examples are vaccinations and education. They are the opposite of negative externalities, goods with positive externalities tend to be under-produced. If the external benefits were taken into account then the supply curve would shift to the right, lowering price and increasing production. The under-production here is another form of market failure.

Enjoy. :)

Demand and Supply (Microeconomics)

This post will broken down into demand, supply and then demand with supply. Lets go...

Firstly, demand. Demand is the willingness and ability to buy a good at any given price. It is shown by a demand curve on a supply and demand diagram, and it shows the relationship between quantity demanded and price. There are two types of demand, effective demand and notional demand. Effective demand is the willingness and ability to buy a good, whereas notional demand is the desire for a good. The relationship between price and demand is inverse... so the lower the price - the higher the demand. There are many factors that determine the demand of a good, they are:

• Tastes or preferences - If a good is currently 'in', or the taste for a product increases then demand will increase. If it's out of fashion or the taste for it decreases then demand will decrease.
• The number of consumers - Simply put, more consumers will generally increase demand... less consumers will decrease demand.
• The income of consumers - If income increase then demand for superior goods such as Bentleys or TVs increases and vice versa. For inferior goods, such as tesco value food, as income increases demand decreases as consumers move to better quality goods. 
• Price of related goods - Using phones as an example, if Nokia phones are really expensive then demand for Samsung phones may increase. Opposite will happen if Nokia phones and really cheap. 

Now onto supply. Supply is the quantity of a product that producers are willing to provide at different market prices over a period of time. The relationship between price and supply is fairly obvious, the higher the price - the more producers are willing to supply to the market (higher supply). The determinants of supply are:

• Production costs - If production costs rise you'd expect a fall in supply, if they fall you'd expect a rise in supply. If its cheaper to make a good, then more will be produced.
• Size and nature of industry - In a competitive industry, any changes in cost will effect supply, however in a market with only one or two major players, any changes in cost can be passed onto the consumers without having to change supply.
• Government policy - Governments may change taxes, or introduce legislation restricting supply. Each would have an effect on supply.
• Natural disaster - Something such as a hurricane may wipe out workers or factories, thus decreasing supply.

When you combine a supply curve and a demand curve onto one diagram, we get presented with a price. The supply and demand diagram is usually set up with price up the y axis and quantity along the x axis. Here is an example...

This is a simple demand and supply diagram, which shows us how prices are determined. The point 'PQ' on the diagram is where the supply curve and the diagram curve meet, meaning the position where both buyers are willing to buy and sellers are willing to sell -  both parties are satisfied. This point is referred to as the market equilibrium price or the clearing price. 

The equilibrium point isn't set in stone and changes as either the demand or supply curve changes. The next image will show this... 

In this new diagram we can see that supply and demand have both changed. Supply has increased, so the curve has shifted to the right from "supply" to "supply 1". Demand has also increased, and thus the curve has shifted to the right from "demand" to "demand 1". The result of this is a new market equilibrium point of 'P-Q1'. What this shows is that any changes in supply or demand will result in a new equilibrium price.

That's all the basics for supply and demand, the next post will be about complimentary and sustitute goods. Thanks for reading!