Category Archives: Supply & Demand

Short-selling explained – ‘Trading Places’ movie

The 1983 movie ‘Trading Places’, staring Eddie Murphy and Dan Aykroyd tells the story of an upper class commodities broker Louis Winthorpe III (Aykroyd) and a homeless street hustler Billy Ray Valentine (Murphy) whose lives cross paths when they are unknowingly made part of an elaborate bet.

There is a great part in the movie when they are on the commodities trading floor that explains price and scarcity. Winthorpe and Valentine are up against the Duke Brothers in the Frozen Concentrated Orange Juice (FCOJ) futures market.

How a futures market works
As opposed to traditional stock/shares futures contracts can be sold even when the seller doesn’t hold any of the commodity. For instance a contract of $1.30 per pound for a 1000 pounds of FCOJ in February indicates that the seller is compelled to provide the produce at that time and the buyer is compelled to buy the produce.

Here’s how it worked in the movie

The Duke Brothers believe they have inside knowledge about the crop report for the orange harvest over the coming year. They are under the impression that the report will state the harvest will be down on expectations which will necessitate greater demand for stockpiling FCOJ – this will mean more demand and a higher price. Therefore at the start of trading the Dukes representative keeps buying FCOJ futures. Others saw they were only buying and wanted in on the action, those that had futures were not willing to sell so the price kept rising. However the report was fake and Winthorpe and Valentine had access to the genuine report which stated that the orange harvest had not been affected by adverse weather conditions. Knowing this they wait till the the price of FCOJ reaches $1.42 and start to sell future contracts.

Then when the crop report is announced and it indicates a good harvest investors sell their contracts and the price drops very quickly. The Dukes are unable to sell their overpriced contracts and are therefore obliged to buy millions of units of FCOJ at a price which exceeds greatly the price which they can sell them for. In the meantime Winthorpe and Valentine for every unit they sold at $1.42 they only have to pay $0.29 to buy it back to fulfill their obligation. This results in a profit of $1.13 per unit.

War on drugs – focus on supply or demand?

Been looking at Price Elasticity of Demand with my AS Level class and discussed the drug industry with reference to Tom Wainwright’s book “Narconomics: How to Run a Drug Cartel”. He also wrote an article for the Wall Street Journal on “How economists would wage the war on drugs”. Essentially, the war on drugs is being lost. Badly. As Wainwright notes:

The number of people using cannabis and cocaine has risen by half since 1998, while the number taking heroin and other opiates has tripled. Illegal drugs are now a $300 billion world-wide business, and the diplomats of the U.N. aren’t any closer to finding a way to stamp them out.

This failure has a simple reason: Governments continue to treat the drug problem as a battle to be fought, not a market to be tamed. The cartels that run the narcotics business are monstrous, but they face the same dilemmas as ordinary firms-and have the same weaknesses.

El Salvador – a leader of one of the country’s two gangs has a human resource issue with high turnover of employees.

Mexico – the Zetas cartel franchises its brand like McDonalds which in turn has led to arguments over territory.

Rich countries – street corner dealers are struggle to compete on price and quality with the ‘dark web’. It is a similar scenario with Amazon.

To combat the drug trade governments have focused on restricting the supply. Each year acres of coca plants and manufacturing activities are destroyed but the price has remains around $150-$200 per pure gram for the past 20 years. How have the cartels managed to keep this price?

However, supply of drugs might not even be appreciably reduced when drug crops are targeted. Wainwright points out that:

  1. Drug cartels are a monopsony – they are a single buyer of Andean coca leaves, so they have market power over the price of leaves (i.e. the cartels have the ability to strongly influence the market price of coca leaves). So if some crops are wiped out, the price is unlikely to rise because of the cartels’ market power.
  2. The price of cocaine is so much higher than the crop input costs that even a large increase in crop prices would have little effect on the market price of cocaine (i.e. even a big increase in the price of coca leaves would lead to only a small shift in the supply curve for cocaine).

Also because of its addictive nature demand for drugs is relatively inelastic – the decrease in quantity demanded is less than the percentage increase in price. Therefore reduced supply and a higher price doesn’t change demand that much.

Demand-Side interventions seem to be a better option and they are also a lot cheaper. Weighing up reducing supply by destroying coca crops in remote areas against drug education in schools and you find the latter is a much more plausible option. Tom Wainwright’s explain this below in his talk to the Cato Institute below:

A dollar spent on drug education in U.S. schools cuts cocaine consumption by twice as much as spending that dollar on reducing supply in South America

Bigger loses have be inflicted on cartels with some US states making marijuana legal.

Milk prices on the up – supply and demand

Demand – this has been healthy especially from China as higher domestic milk prices there has likely led to greater milk imports from New Zealand. The number of unsatisfied buyers at recent auctions has been elevated and forward price curves for major products are relatively flat suggesting fundamental strength rather than a near term short squeeze.

Supply – NZ supply as milk production dipped below usual levels in November and with drier weather in North Island extra supply for this time of year will be unlikely.

Fonterra lifted its 2020/21 milk price forecast to a range of $6.90 to $7.50 (up from $6.70 to $7.30 previously) – see graph below.

BNZ Bank – Economy Watch

This being said Fonterra has to be cautious with:

  • NZ weather conditions – drought can increase the price of feed and deplete water stores for cows and can reduce the ability of dairy farmers to grow feed and ultimately reduce their herd.
  • challenges from further escalation of COVID – global demand could soften as a result of extended shutdowns, or large falls in discretionary spending.
  • increasing milk production in the Northern Hemisphere – In Europe and the US, previous dairy stockpiles are now reaching commercial markets which will depress prices.
  • Strong NZ$ – milk is sold on the GlobalDairyTrade (see below) in US$. If the NZ$ gets stronger it will take more US$ to convert into NZ$ so higher domestic milk prices.

How does the GDT work?

GlobalDairyTrade trading events are conducted as ascending-price clock auctions run over several bidding rounds.  In each auction a specified maximum quantity of each product is offered for sale at a pre-announced starting price. Bidders bid the quantity of each product that they wish to purchase at the announced price. If the price of a product increases between rounds, to ensure their desired quantity a bidder must bid their desired quantity at the new, higher price. Generally, as the price of a product increases, the quantity of bids received for that product decreases. The trading event runs over several rounds with the prices increasing round to round until the quantity of bids received for each product on offer matches the quantity on offer for the product (as shown in the diagram below). Each trading event typically lasts approximately 2 hours.

Cobweb Theory and Price Elasticity

I have blogged on this topic before and although not in the NCEA or CIE syllabus’ I find it useful theory to mention when doing supply, demand and elasticity. Agricultural markets are particularly vulnerable to price fluctuations. many agricultural products have inelastic demand and inelastic supply. This means that any change in demand or supply has more of an impact on price than on quantity. Price fluctuations can also arise due to the time lag between planning agricultural production and selling the produce. The cobweb theory (so-called because of the appearance of the diagram) suggests that price can fluctuate around the equilibrium for some time, or even move away from the equilibrium. Dairy farmers base their production decisions on the price prevailing in the previous time period.


The supply of dairy products in New Zealand fits this assumption – farmers make their production decisions today, but the dairy cooperatives (Fonterra, Westland, etc.) don’t make a final decision on the price farmers will receive until close to the end of the season.

Cobweb scenarios:
Convergent
At the equilibrium point, if the demand curve is more elastic than the supply curve, we get the price volatility falling, and the price will converge on the equilibrium. For example:

  • Adverse weather conditions means their is a poor crop – Qt
  • The excess demand causes the price to rise – Pt
  • Because of the higher price famers plant more crops and therefore greater supply – Qt+1
  • With supply so high prices drop to meet demand – Pt+1
  • Lower prices mean that famers supply less to the following year – Qt+2
  • This results in higher prices again – Pt+2
  • Because of the higher price famers plant more crops and therefore greater supply – Qt+3 etc.
  • This process continues until you get to an equilibrium as the PED is greater than the PES – supply curve is steeper than the demand curve.
Source: Policonomics

Continuous
This is occurs where there is a continuous fluctuation between two equilibriums – Pt and Pt+1. The PED and the PES are equal to each other.
Divergent
Prices will diverge from the equilibrium when the PES greater than the PED at the equilibrium point – i.e.the demand curve is steeper than the supply – price changes could increase and the market becomes more changeable.

Even though these three diagrams show very different results they are dependent on the PES and the PED of the market.

Source:
https://policonomics.com/lp-closed-economy-cobweb-model/

Ludicrous regulations of the US Airline Industry and Contestable Markets

With Auckland now at COVID-19 Alert Level 3 and schools operating online we continued going through the A2 syllabus and discussed Contestable Markets using Webex. I used this clip from Commanding Heights to show how regulated the US airline industry was during the 1970’s. Regulations meant that major carriers like Pan Am never had to compete with newcomers. However an Englishman named Freddie Laker was determined to break this tradition and set-up Laker airways to compete on trans-atlantic flights. He offered flights at less than half the price of what Pan Am charged. Alfred Kahn was given the task by the then President Jimmy Carter to breakup the Civil Aeronautics Board (the regulatory body) and he wanted a leaner regulatory environment in which the market was free to dictate price. There is a piece in the clip that shows how ludicrous some of the regulations were:

When I got to the Civil Aeronauts Board, the biggest division under me was the division of enforcement – in effect, FBI agents who would go around and seek out secret discounts and then impose fines. We would discipline them. It was illegal to compete in price. That means it was illegal to compete in the discounts you offer travel agents. So we regulated travel agents’ discounts. Internationally, since they couldn’t cut rates, they competed by having more and more sumptuous meals. We actually regulated the size of sandwiches. Alfred Kahn

When the CAB was closed down competition was the rule and the industry had vastly underestimated the demand for air travel at lower prices – a very elastic demand curve – see graph below.

In the A2 course contestable markets is a popular essay question and is usually combined with another market structure.

What is a contestable market?

• One in which there is one firm (or a small number of firms)
• Because of freedom of entry and exit, the firm faces competition and might operate in a way similar to a perfectly competitive firm
• The threat of “hit and run entry” from new firms may be sufficient to keep the industry operating at a competitive price and output
• The key requirement for a contestable market is the absence of sunk costs – i.e. costs that cannot be recovered if a business decides to leave a market
• When sunk costs are high, a market is more likely to produce an price and output similar to monopoly (with the risk of allocative inefficiency and loss of economic welfare)
• A perfectly contestable market occurs only when entry and exit into and out of a market is perfectly costless
• Contestable markets are different from perfect competitive markets
• It is possible for one incumbent firm to dominate the industry
• Each existing firm in the market produces a differentiated product (i.e. goods and services are not perfect substitutes for each other)

There are 3 conditions for market contestability:

• Perfect information and the ability and or legal right to use the best available technology
• Freedom to market / advertise and enter a market
• The absence of sunk costs

Example
• Liberalisation of the US Airline Industry in the 1970’s and the European Airline Market in late 1990s
• Traditional “flag-flying” airlines faced new competition
• Barriers to entry in the industry were lowered (including greater use of leased aircraft)
• New Entrants – easyJet- Ryanair

The challenges for the oil market with COVID-19

Another good video from the FT this time on the future of the oil industry. There is a movement towards more cleaner fuels by major companies in Europe but the same can’t be said about the US. Oil producing countries have been hit by lower prices but some like Saudi Arabia have sufficient reserves to fall back whilst others like Nigeria and Venezuela are financially exposed. Below is a graphic from the video looking at supply and demand – useful for an introductory lesson on the market.

Source: FT

Income Elasticity of Demand and Consumer Purchases Post-Covid

I came across this material on the blog ‘Sex, Drugs and Economics’ which discusses Bruce Wydick’s post on his blog ‘Across Two Worlds’. This is very useful for NCEA Level 3 and CIE AS Level Unit 2 both of which look at Income Elasticity of Demand.

Wydick looks at who is most likely to do well and who is likely to suffer in a post-covid environment. A typical recession is generally caused by supply-side factors (oil crisis years of 1973 – prices up by 400% – 1979 – prices up by 200%) or demand-side impact (loss of business confidence and consumer confidence). Covid-19 is very different as it is a complete shut-down of certain businesses and it forced people to stop buying things that they normal do. Wydick puts goods and services into two categories:

Snap-Back goods and services – things we couldn’t buy during the Level 4 lock-down period but were purchased when we went to Level 3. Pent up demand meant that purchases of these goods and service might have been higher than normal – buying less now means buying more later.

Gone Forever – as it states. Invariably this generally refers to services like air travel, tourism, haircuts, public transport and entertainment. When it becomes safe to have a haircut you still only get one haircut as the rest of your haircuts have disappeared and there is no catch-up spending like with snap-back goods.

These are the differences between goods with low versus high income elasticity. Income elasticity of demand measures the responsiveness of quantity demanded to changes in income. We can have different types of normal goods. If a 10% increase in income brought about a 10% increase in quantity demanded, we can say the income elasticity of demand is unitary. If EY>1 we classify the good as a luxury, and if EY<1, a necessity.

Income elasticity of demand will also affect the pattern of demand over time. For normal luxury goods, whose income elasticity of demand exceeds +1, as incomes rise, the proportion of a consumer’s income spent on that product will go up. For normal necessities (income elasticity of demand is positive but less than 1 and for inferior goods (where the income elasticity of demand is negative) – then as income rises, the share or proportion of their budget on these products will fall. Wydick puts the different types of purchases in a simple 2 x 2 matrix“Snap-Back” vs. “Gone Forever” and High vs. Low income elasticity. 

It then becomes easy to see which industries are in the most trouble in 2020.  So, when goods and services are both “gone forever” and have a high income elasticity, we can expect the impact of the coronavirus pandemic to be most severe. Wydick identifies air travel, tourism, sporting events, hospitality, and transport (but not public transport). Everything else either snaps back and experiences some catch-up spending, or isn’t as affected by lower incomes. Goods that have a high income elasticity means that when you lose your job during the recession, you and others like you are even less likely to buy these things. For New Zealand the decline of the tourism industry is a significant hit to GDP and employment in this sector.

What causes a recession? TED-Ed

Showed this to my IGCSE class today – great video which is well put together with good examples that explain a recession and its causes. Particularly apt for today’s economic environment. Makes good use of supply and demand graphs as well as supply side and demand side variables. Detailed explanation of the business cycle. Useful for NCEA Level 2 growth standard.

AS Revision – Indirect Tax

The AS multiple-choice paper is coming up and here is this graphic to explain indirect taxes – a popular question. An indirect tax will have the following effects on the market:

Indirect Tax

• The supply curve shifts vertically upwards(effectively a shift to the left) by the amount of the tax(gf) per unit. The price increases but not by the full amount of the tax. This is because of the slopes of the demand and supply curves.
• The consumer surplus is reduced from acp to agb. The portion gbhp of the old consumer surplus is transferred to government in the form of tax.
• The producer surplus is reduced from pce to fde. The portion phdf of the old producer surplus is transferred to the government in the form of tax.
• The market is no longer able to reach equilibrium, and there is a loss of allocative efficiency resulting in the deadweight lost shown by the area bcd. This represents a loss of both consumer surplus bhc and the producer surplus hcd that is removed from the market. The deadweight loss also represents a loss of welfare to an individual or group where that loss is not offset by a welfare gain to some other individual or group.

AS & A2 Revision – How PED varies along a demand curve

Been doing some more revision sessions on CIE AS economics and went through how the elasticity of demand varies along a demand curve. Notice in Case A that the fall in price from Pa to Pb causes the the total revenue to increase therefore it is elastic – the blue area (-) is less than the orange area (+). In Case B the opposite applies – as the price decreases from Pa to Pb the total revenue decreases therefore it is inelastic – the blue area (-) is greater than the orange area (+). In Case C the drop in price causes the same proportionate change in quantity demanded, therefore there is no change in total revenue – it is unitary elasticity.

Remember where MR = 0 – PED = 1 on the demand curve (AR curve). A particularly popular question at A2 level is ‘where on the demand curve will a profit maximising firm produce at?’. As MC = MR above zero the imperfect firm always produces on the elastic part of the demand curve.