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# Economic equilibrium

❶We next examine what happens at prices other than the equilibrium price. Not all equilibria are "stable" in the sense of Equilibrium property P3.

## What Is the Formula for Total Revenue?   This is a graphical representation of the market behavior and clearly shows the intersection point in the graph itself. You can see the competitive equilibrium in above curve as quantities and the price of LKR By substituting demand and supply formula to the given example equilibrium quantity and price can be calculated.

In other words, it is the demand and supply quantities at price zero. Therefore, demand and supply equations can be formulated as follows. By substituting P and Q values to both demand and supply equations, equilibrium price and quantity can be found as follows.

The equilibrium shows following special features in a competitive market. Likewise where the price is below the equilibrium point there is a shortage in supply leading to an increase in prices back to equilibrium. Not all equilibria are "stable" in the sense of Equilibrium property P3. It is possible to have competitive equilibria that are unstable. However, if an equilibrium is unstable, it raises the question of how you might get there.

Even if it satisfies properties P1 and P2, the absence of P3 means that the market can only be in the unstable equilibrium if it starts off there. In most simple microeconomic stories of supply and demand a static equilibrium is observed in a market; however, economic equilibrium can be also dynamic.

Equilibrium may also be economy-wide or general , as opposed to the partial equilibrium of a single market. Equilibrium can change if there is a change in demand or supply conditions. For example, an increase in supply will disrupt the equilibrium, leading to lower prices.

Eventually, a new equilibrium will be attained in most markets. Then, there will be no change in price or the amount of output bought and sold — until there is an exogenous shift in supply or demand such as changes in technology or tastes. That is, there are no endogenous forces leading to the price or the quantity. The Nash equilibrium is widely used in economics as the main alternative to competitive equilibrium.

It is used whenever there is a strategic element to the behavior of agents and the "price taking" assumption of competitive equilibrium is inappropriate. The first use of the Nash equilibrium was in the Cournot duopoly as developed by Antoine Augustin Cournot in his book. This determines the revenues of each firm the industry price times the quantity supplied by the firm. The profit of each firm is then this revenue minus the cost of producing the output. Clearly, there is a strategic interdependence between the two firms.

If one firm varies its output, this will in turn affect the market price and so the revenue and profits of the other firm. We can define the payoff function which gives the profit of each firm as a function of the two outputs chosen by the firms.

Cournot assumed that each firm chooses its own output to maximize its profits given the output of the other firm. The Nash equilibrium occurs when both firms are producing the outputs which maximize their own profit given the output of the other firm. In terms of the equilibrium properties, we can see that P2 is satisfied: P1 is satisfied since the payoff function ensures that the market price is consistent with the outputs supplied and that each firms profits equal revenue minus cost at this output.

Is the equilibrium stable as required by P3? Cournot himself argued that it was stable using the stability concept implied by best response dynamics. The reaction function for each firm gives the output which maximizes profits best response in terms of output for a firm in terms of a given output of the other firm. In the standard Cournot model this is downward sloping: Best response dynamics involves firms starting from some arbitrary position and then adjusting output to their best-response to the previous output of the other firm.

So long as the reaction functions have a slope of less than -1, this will converge to the Nash equilibrium. However, this stability story is open to much criticism. For example, food markets may be in equilibrium at the same time that people are starving because they cannot afford to pay the high equilibrium price. Indeed, this occurred during the Great Famine in Ireland in —52, where food was exported though people were starving, due to the greater profits in selling to the English — the equilibrium price of the Irish-British market for potatoes was above the price that Irish farmers could afford, and thus among other reasons they starved.

In most interpretations, classical economists such as Adam Smith maintained that the free market would tend towards economic equilibrium through the price mechanism.

That is, any excess supply market surplus or glut would lead to price cuts , which decrease the quantity supplied by reducing the incentive to produce and sell the product and increase the quantity demanded by offering consumers bargains , automatically abolishing the glut. I am already noted this in my hand note. You know I am a student of mathematics. By the way, the post is really impressive. Thank you so much and I appreciate that kind of work.

How do I determine the equilibrium market price and quantity. I am so much excited after reading equilibrium price and quantity. Your math is very much innovative and much helpful for any industry as well as for person. Wow, this site is awesome guys! I think this is a really good article. You make this information interesting and engaging.

I guess I am not only one having all the enjoyment right here! Lara Croft Tomb Raider Jacket. Assist to solve for equilibrium quantity and equilibrium price. Calculate the equilibrium price and equilibrium quantity. Keep posting the good work. Some really helpful information in there. Nice to see your site. Back to general equilibrium. If demand is low supply is high. How to find equilibrium price and quantity mathematically.

Updated August with more examples and links to relevant topics. To solve for equilibrium price and quantity you shoul Updated August of to include more information and examples. Previous posts have gone over the description and construction of the p How to calculate point price elasticity of demand with examples. Point elasticity is the price elasticity of demand at a specific point on the demand curve instead of over a range of the demand curve.

How to calculate deadweight loss; easy 4 step method. Many times, professors will ask you to calculate the dea What causes shifts in the IS or LM curves? This post was updated in August to include new information and examples. This post goes over the economics and intuition of the IS How to solve elasticities problems in economics.

Calculating elasticities is actually very easy. You just need to know several of the values, then plug them into their proper place. How to draw a PPF production possibility frontier. ## Main Topics

The equilibrium price is the price at which the quantity demanded equals the quantity supplied. Graphically, it is the point at which the two curves intersect. Graphically, it is the point at which the two curves intersect.

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