Evergreening This refers to a process supposedly used to extend patents on known drugs by tweaking them.
A generic drug (generic drugs, short: generics) is a drug which is produced and distributed without patent protection. These products are comparable to brand/reference listed drug product in dosage form, strength, route of administration, quality and performance characteristics, and intended use. The cost of generic durg is significantly less than brand listed drug so it is more affordable to common people.
Quasi Rent- Quasi-rent is a term in economics that describes certain types of returns to firms. Quasi-rent differs from pure economic rent in that it is a temporary phenomenon. They can arise because in the short-run potential competitors face barriers entry. They can also arise due to government intervention, such as the granting of patents or other legal protections for intellectual property.
The concept of quasi-rent owes its origin to Dr. Alfred Marshall Dr. Marshall is of the opinion that it is not possible .for human beings to increase the supply of land. It is fixed by Nature. If price of a produce rises, the surface of earth cannot be increased and if price falls, it cannot be decreased. But by appliance of machine which are the product of human efforts, the supply can be increased or decreased if a fairly long period of time is allowed. Marshall is of the view that a differential surplus which arises from a factor of production, whose supply is fixed for all times to come should be named as rent but a temporary gain which a factor or production earns due to temporary limitation of its supply should be called quasi-rent. For instance, the demand for shaving blades suddenly goes up in Pakistan and the price of a packet containing 10 blades rises from Rs. 15 to Rs. 20. The entrepreneurs lured by high profits will naturally try to produce more blades. They may try to meet the demand by working the factory for 24 hours. Let us suppose, the supply is still short .of demand and the price remains at Rs. 20 per packet. The new entrepreneurs attracted by high profits will establish new factories. A factory cannot be established in a day. It needs time for installing new machinery. When new plants are set up, the supply of blades will increase and the price comes down to the level of their costs of production (Rs. 15). The temporary gain which the old factories have earned during the period when new factories’ were not installed, is regarded as earned during the period when new factories were not installed is regarded as quasi-rent. Quasi-rent is, thus, a temporary gain which is earned by a factor of production due to the temporary limitation of its supply.
Walrasian tatonnement Walras proposed a dynamic process by which general equilibrium might be reached, that of the tâtonnement or groping process.The tatonnement process is a model for investigating stability of equilibria. Prices are announced (perhaps by an "auctioneer"), and agents state how much of each good they would like to offer (supply) or purchase (demand). No transactions and no production take place at disequilibrium prices. Instead, prices are lowered for goods with positive prices and excess supply. Prices are raised for goods with excess demand. The question for the mathematician is under what conditions such a process will terminate in equilibrium in which demand equates to supply for goods with positive prices and demand does not exceed supply for goods with a price of zero. Walras was not able to provide a definitive answer to this question A Walrasian auction, introduced by Leon Walras, is a type of simultaneous auction where each agent calculates its demand for the good at every possible price and submits this to an auctioneer. The price is then set so that the total demand across all agents equals the total amount of the good. Thus, a Walrasian auction perfectly matches the supply and the demand. Walras suggests that equilibrium will be achieved through a process of tatonnement or groping. The Walrasian auctioneer is the presumed auctioneer that matches supply and demand in a market of perfect competition. The auctioneer provides for the features of perfect competition: perfect information and no transaction costs. The process is called tâtonnement, or groping, relating to finding the market clearing price for all commodities and giving rise to general equilibrium. The tâtonnement process works as follows. Prices are cried, and agents register how much of each good they would like to offer (supply) or purchase (demand). No transactions and no production take place at disequilibrium prices. Instead, prices are lowered for goods with positive prices and excess supply. Prices are raised for goods with excess demand. The tâtonnement mechanism has the following characteristics: there is only one price at any time; there is an information mechanism notifying all traders of the price; there is a mechanism for determining quantities offered for sale and purchase at the price; and transactions at nonequilibrating prices are forbidden. In addition, the Walrasian pricing rule is utilized by the auctioneer: the change in price has the same sign as excess demand. The treatment variable used in the experimental design is the degree of segregation of buyers and sellers. Complete segregation means sellers cannot discover the number of buyers and buyers cannot discover the number of sellers at an announced price. The results show that the auction mechanism is stable: it exhibits strong convergence properties and efficiency levels averaging better than 97%. Segregation of the buyers from the sellers leads to a significant difference in underrevelation of demand relative to supply. The question for the economist is under what conditions such a process will terminate in equilibrium in which demand equates to supply for goods with positive prices and demand does not exceed supply for goods with a price of zero. Although Walras was not able to provide a definitive answer to this question subsequent researchers, such as Arrow and Debreu, have provided proofs of existence under some conditions (of which the strongest one is the convexity of preferences). However, the Sonnenschein-Mantel-Debreu Theorem states that an equilibrium need not be unique. A recent article by Richter and Wong contests the Arrow-Debreu proof and claims the following holds with respect to the computation of Walrasian equilibria: The Arrow-Debreu conditions are not sufficient to guarantee existence of a computable equilibrium. The rate of approximation towards an equilibrium (as defined by the current price set), cannot be given under any algorithm.