Perfect Competition

Perfect competition is a very unrealistic market structure. We'll discuss the characteristics of it later, but for now we have to understand that it is a theoretical concept. If the world was perfect then in most cases we'd have markets operating 'perfectly'. The world isn't perfect and therefore actually seeing perfect competition in reality is a long shot. The major assumption we make is that firms are price takers. By this we mean that each firm alone has no influence over the market price because of their relative size. They take the price they can get as given and perceive it to be constant. Therefore the demand curve for a firm in perfect competition is horizontal - the can sell as much as they want but only at the market set price. Any higher and they wouldn't sell a thing, any lower and they'd make a loss in the long run.

Here we have a typical perfect competition scenario in the short run. On the left is the market where the market price is determined by the supply and demand for the good. The firm, on the right, takes the market price as given and as their price. Average revenue and marginal revenue is the same as the demand curve because we are looking at a constant price for the good. Production takes place at the point where MC = MR, anywhere before this point and more profit can be made, anywhere after this point and profit falls. If you look at the diagram, at the point MC = MR, the average cost is below the average revenue. This means profit is available, which is shown by the yellow area. In the short run the supernormal profit will be (AR-AC) x Qe.

Now, above I've just said that AR and MR are the same as demand because price is constant. You want proof I hear? Sure thing. Average revenue = Total revenue / Quantity. Total revenue is actually price x quantity. Therefore average revenue can be re-written as (price x quantity) / quantity. Quantity cancels out leaving price ~ average revenue = price. Marginal revenue = the change in total revenue / the change in quantity. Substituting in what total revenue actually is we have the change in (price x quantity) / change in quantity. The change in quantity cancels out leaving price ~ marginal revenue = price. Boom!

But, we have only discussed the short run. These supernormal profits don't go unnoticed - they attract new firms into the industry. Supply now shifts out.

The price falls due to the increase in supply. On the right diagram we can see that it's fallen to the point where MC = MR = AC. This means that supernormal profit is no longer being made, it has been competed away. At this point no more firms will enter the industry because there won't be the pull of supernormal profits. Therefore, in the long run there is no supernormal profit to be made in a perfectly competitive market.

It seems risky to the normal person, producing right on the point of breaking even. This is true to a certain extent. Shocks to the system could cause demand to fall, what would happen to the firm then?

Here we have the case of a fall in demand in the market causing a fall in price. The firm was initially producing where MC = MR = AC, but now the fall in price means that if they produce at MC = MR they will actually be making a super-normal loss. This point would be below average costs and therefore the enclosed area on the right hand diagram would be loss. Would they carry on producing? Surprisingly, yes, in this case the firm would. To understand this we have to look at the breakdown of the costs. In the short run we know capital is fixed and labour is variable. Therefore the average variable cost for the firm in a simple world would be labour costs / quantity. As long as the average revenue (demand curve) is greater than the average variable costs then the firm will continue producing. This means they can cover the costs of labour and make some contribution to the fixed costs. If they couldn't cover the average variable costs it would be better for the firm to stop producing, lay off all the workers and only lose the fixed costs.

Some other things we can state is that the short run supply curve for a firm in a perfectly competitive market is the marginal cost curve until the point where price equals average variable cost. As we said above, below that point the firm will stop supplying the market. In the long run the firms supply curve is horizontal at the minimum average cost.

All we need to do now is sum up whether perfect competition is a good thing. It definitely has its advantages, they are as follows:

·         It's efficient - production occurs at the lowest average cost which is the most efficient point.

·         Competition - competition in an industry forces firms to be more efficient.

·         Price is influenced by demand - the market is essentially run by consumers, it responds to their behaviour.

·         No supernormal profits in the long run.

It really has few disadvantages though. You could state the fact that it isn't realistic as a disadvantage, I guess. In real life it would be rare to find a market with freedom of entry/exit, identical products, price taking firms, etc. One point that could be made about the lack of super-normal profit is the lack of innovation. Innovation tends to be fueled by profit, without profit there is little room for firms to innovate. Innovation is one thing that can lead to a more efficient market, so in perfect competition once the efficient point is reached it will not be made any more efficient. Comprende?

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.

Principles of Economics: Revenue (Microeconomics)

* Sorry about the delay with this post, I've had a busy week and have just got round to writing this up. But I'll have another one up tomorrow as well to make up for it. *

Right, today's post will be relating to revenue and more specifically a firms revenue. We'll start with a few of the basic bits of terminology that I'll be using throughout this post. Firstly, total revenue. This is fairly self-explanatory but I'll give a definition anyway. Total revenue is a firms total earnings in a period of time from the sale of a particular amount of goods, the formula is better known as price x quantity. Average revenue next and this is the amount a firm earns for each unit sold, the formula for this is (total revenue) / (quantity) which you may have noticed just equals price. Marginal revenue is the final term, this refers to the extra revenue gained from selling one more unit of a good. The formula for marginal revenue is (change in total revenue) / (change in quantity).

We'll first look at the revenue curves for a small firm. We'll be assuming this firm is in a perfectly competitive market (Will do a blog post on this later today/tomorrow). Basically, this means that the firms are generally too small to have any effect on the price of the good they are selling. If they raise their price no-one will buy from them, if they lower their price they will find an overwhelming demand and probably be charging less than the cost to produce the good. That being said, the market forces determine the price the firm has to charge.

As you can see here, the demand and supply have met in the market and this has created a price for the good. The firm, shown on the left has a demand curve of this price because consumers will only buy from the firm at this price. No matter the quantity, the price will remain the same. Another note on this, D = AR = MR because the price is constant. The average revenue and marginal revenue will always be the same because we are working with a constant price.  We can model the total revenue of a firm as well. This is simple, first we create a table with the quantity supplied, price and total revenue. We then plot this table. Simple.

Simple as that for a total revenue curve for a small firm. However, when it comes to larger firms and the price of the good does vary with output we are struck with a different scenario. The average revenue curve is still equal to the price and will be the demand curve, but this time it will be downward sloping as with the normal characteristic of demand. The marginal revenue curve will also be downward sloping, but at a faster rate than the average revenue curve and will more than likely reach negative values. This is due to the diminishing marginal rate of production, the marginal revenue falls with each additional good you produce up to a point where producing another good will generate no additional revenue and may even decrease revenue. Before the quantity where marginal revenue equals zero, the average revenue is elastic because an increase in quantity will lead to a rise in revenue. After this point, it's inelastic because a rise in quantity leads to a fall in total revenue. 

And all that's left to add to this is the shape of the total revenue curve when the price varies with output. I should note, this happens in larger firms when they can effect the market price. The total revenue curve would be somewhat hill shaped. It would slope up, reach a peak at some unknown point and then slop down again afterwards. You may be thinking "Ok, great... Why?"! Well, this will come in useful in the next posts when we look at profit maximisation of a firm. 

Thank you for reading again, keep watching for the next few posts which will relate and link to this one. Have a good day!

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.