Modules, Structures, and Classes

There are just three ways to organize a VB.NET application. ModulesStructuresClasses But most technical articles assume that you already know all about them. If youre one of the many who still have a few questions, you could just read past the confusing bits and try to figure it out anyway. And if you have a lot of time, you can start searching through Microsofts documentation: A Module is a portable executable file, such as type.dll or application.exe, consisting of one or more classes and interfaces.A Class statement defines a new data type.The Structure statement defines a composite value type that you can customize. Right, then. Any questions? To be a bit more fair to Microsoft, they have pages and pages (and more pages) of information about all of these that you can wade through. And they have to be as exact as possible because they set the standard. In other words, Microsofts documentation sometimes reads like a law book because it is a law book. But if youre just learning .NET, it can be very confusing! You have to start somewhere. Understanding the three fundamental ways that you can write code in VB.NET is a good place to start. You can write VB.NET code using any of these three forms. In other words, you can create a Console Application in VB.NET Express and write: Module Module1Sub Main()MsgBox(This is a Module!)End SubEnd ModuleClass Class1Sub Main()MsgBox(This is a Class)End SubEnd ClassStructure Struct1Dim myString As StringSub Main()MsgBox(This is a Structure)End SubEnd Structure This doesnt make any sense as a program, of course. The point is that you dont get a syntax error so its legal VB.NET code. These three forms are the only way to code the queen bee root of all of .NET: the object. The only element that interrupts the symmetry of the three forms is the statement: Dim myString As String. That has to do with a Structure being a composite data type as Microsoft states in their definition. Another thing to notice is that all three blocks have a Sub Main() in them. One of the most fundamental principals of OOP is usually called encapsulation. This is the black box effect. In other words, you should be able to treat each object independently and that includes using identically named subroutines if you want to. Classes Classes are the right place to start because, as Microsoft notes, A class is a fundamental building block of object-oriented programming (OOP). In fact, some authors treat modules and structures as just special kinds of classes. A class is more object oriented than a module because its possible to instantiate (make a copy of) a class but not a module. In other words, you can code ... Public Class Form1Private Sub Form1_Load( _ByVal sender As System.Object, _ByVal e As System.EventArgs) _Handles MyBase.LoadDim myNewClass As Class1 New Class1myNewClass.ClassSub()End SubEnd Class (The class instantiation is emphasized.) It doesnt matter whether the actual class itself, in this case, ... Public Class Class1Sub ClassSub()MsgBox(This is a class)End SubEnd Class ... is in a file by itself or is part of the same file with the Form1 code. The program runs exactly the same way. (Notice that Form1 is a class too.) You can also write class code that behaves much like a module, that is, without instantiating it. This is called a Shared class. The article Static (that is, Shared) versus Dynamic Types in VB.NET explains this in much more detail. Another fact about classes should also be kept in mind. Members (properties and methods) of the class only exist while the instance of the class exists. The name for this is scoping. That is, the scope of an instance of a class is limited. The code above can be changed to illustrate this point this way: Public Class Form1Private Sub Form1_Load( _ByVal sender As System.Object, _ByVal e As System.EventArgs) _Handles MyBase.LoadDim myNewClass As Class1 New Class1myNewClass.ClassSub()myNewClass NothingmyNewClass.ClassSub()End SubEnd Class When the second myNewClass.ClassSub() statement is executed, a NullReferenceException error is thrown because the ClassSub member doesnt exist. Modules In VB  6, it was common to see programs where most of the code was in a module (A .BAS, file rather than, for instance, in a Form file such as Form1.frm.) In VB.NET, both modules and classes are in .VB files. The main reason modules are included in VB.NET is to give programmers a way to organize their systems by putting code in different places to fine tune the scope and access for their code. (That is, how long members of the module exist and what other code can reference and use the members.) Sometimes, you may want to put code into separate modules just to make it easier to work with. All VB.NET modules are Shared because they cant be instantiated (see above) and they can be marked Friend or Public so they can be accessed either within the same assembly or whenever theyre referenced. Structures Structures are the least understood of the three forms of objects. If we were talking about animals instead of objects,  the structure would be an Aardvark. The big difference between a structure and a class is that a structure is a value type and a class is a reference type. What does that mean? Im so glad you asked. A value type is an object that is stored directly in memory. An Integer is a good example of a value type. If you declared an Integer in your program like this ... Dim myInt as Integer 10 ... and you checked the memory location stored in myInt, you would find the value 10. You also see this described as being allocated on the stack. The stack and the heap are simply different ways of managing the use of computer memory. A reference type is an object where the location of the object is stored in memory. So finding a value for a reference type is always a two step lookup. A String is a good example of a reference type. If you declared a String like this ... Dim myString as String This is myString ... and you checked the memory location stored in myString, you would find another memory location (called a pointer - this way of doing things is the very heart of C style languages). You would have to go to that location to find the value This is myString. This is often called being allocated on the heap. The stack and the heap Some authors say that value types arent even objects and only reference types can be objects. Its certainly true that the sophisticated object characteristics like inheritance and encapsulation are only possible with reference types. But we started this whole article by saying that there were three forms for objects so I have to accept that structures are some sort of object, even if theyre non-standard objects. The programming origins of structures go back to file-oriented languages like Cobol. In those languages, data was normally processed as sequential flat files. The fields in a record from the file were described by a data definition section (sometimes called a record layout or a copybook). So, if a record from the file contained: 1234567890ABCDEF9876 The only way you would know that 1234567890 was a phone number, ABCDEF was an ID and 9876 was $98.76 was through the data definition. Structures help you accomplish this in VB.NET. Structure Structure1VBFixedString(10) Dim myPhone As StringVBFixedString(6) Dim myID As StringVBFixedString(4) Dim myAmount As StringEnd Structure Because a String is a reference type, its necessary to keep the length the same with the VBFixedString attribute for fixed length records. You can find an extended explanation of this attribute and attributes in general in the article Attributes in VB .NET. Although structures are non-standard objects, they do have a lot of capability in VB.NET. You can code methods, properties, and even events, and event handlers in structures, but you can also use more simplified code and because theyre value types, processing can be faster. For example, you could recode the structure above like this: Structure Structure1VBFixedString(10) Dim myPhone As StringVBFixedString(6) Dim myID As StringVBFixedString(4) Dim myAmount As StringSub mySub()MsgBox(This is the value of myPhone: myPhone)End SubEnd Structure And use it like this: Dim myStruct As Structure1myStruct.myPhone 7894560123myStruct.mySub() Its worth your time to play around with structures a bit and learn what they can do. Theyre one of the odd corners of VB.NET that can be a magic bullet when you need it.

Richard Nixon Was The Last Liberal Era - 2168 Words

It can be argued that Richard Nixon was the last liberal president and that his presidency ushered in a conservative era. Both of these arguments are true, however I believe it is more correct to say that his presidency marked a new conservative era. During his time in office, Nixon expanded Great Society legislation, created new and significant federal agencies, and his foreign policy with communism emphasized dà ©tente. However, he did not always agree with the liberal ideologies that he was implementing and, in regards to the anti-war protestors, his administration showed little concern for civil liberties. In comparison to the administrations that followed, he was much more liberal and was the last president to significantly increase†¦show more content†¦Social conservatism generally favors traditional, pro-family values, such as opposition to abortion and same sex marriage. Richard Nixon’s campaign echoed many aspects of the conservative language of the time, bu t ultimately his presidency was liberal, as he subscribed to liberal tendencies, such as broadening social programs and the influence of the federal government. He did not battle the Democrats, who held congress, on domestic issues and even expanded components of President Lyndon B. Johnson’s Great Society. Instead of curtailing the federal government’s role, Nixon created new agencies such as the Environmental Protection Agency, the Occupational Safety and Health Administration, and the National Transportation Safety Board. His administration poured money into social services and environmental initiatives, expanded the food stamp program, and allowed Social Security to expand with inflation. Numerous acts were passed such as the Endangered Species Act and the Clean Air Act. His commitment to protecting the environmental ostracized businesses, natural allies of conservative ideologies, who deemed these regulations burdensome. Nixon broke the mold of conservative polit ics further by presenting a Family Assistance Plan that would guarantee a minimum income for all Americans and by pursuing affirmative action programs to â€Å"upgrade minority employment†. The Family Assistance Plan did not pass in congress and was criticized by

Comparison Between Market Structures Free Essays

string(7666) " from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero\) †¢ Since MR=P\(=D=AR\), when MR=MC, P=MC †¢ When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms †¢ MR = MC where MC is rising \(revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero\) †¢ Since PMR, when MR=MC, PMC MR = MC where MC is rising \(revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero\) †¢ Since PMR, when MR=MC, PMC †¢ MR = MC where MC is rising \(revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero\) †¢ Since PMR, when MR=MC, PMC M eaning of SR Equilibrium †¢ When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms †¢ When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms Meaning of LR Equilibrium Profitability in SR †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Perfect Competition \$ MC AC P0 Supernormal Profits †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Monopolistic Competition \$ MC AC Supernormal Profits †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Oligopoly \$ MC †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Monopoly \$ MC AC Supernormal Profits AR=MR=DD P0 P0 AC Supernormal Profits P0 AR=DD MR Q0 Quantity Q0 Quantity Q0 MR AR=DD MR Quantity Q0 AR=DD Quantity 3 Perfect Competition †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Perfect Competition \$ MC AC P0 AR=MR=DD Monopolistic Competition †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Monopolistic Competition \$ MC AC P0 Oligopoly †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Oligopoly \$ MC AC P0 Monopoly †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Monopoly \$ MC AC P0 AR=DD MR Q0 Quantity Q0 Quantity Q0 MR AR=DD MR Quantity Q0 AR=DD Quantity †¢ Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Perfect Competition \$ MC AC Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Monopolistic Competition \$ AC MC Subnormal Profits †¢ Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Oligopoly \$ MC AC Subnormal Profits †¢ Subn ormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Monopoly \$ AC MC Subnormal Profits P0 Subnormal Profits AR=MR=DD P0 P0 P0 AR=DD MR Q0 Quantity Q0 Quantity Q0 MR AR=DD MR Quantity Q0 AR=DD Quantity Profitability in LR Necessarily makes normal profit because of free entry and exit from the industry †¢ Supernormal profits – beyond optimum capacity \(Overutilisation where AC is rising\) †¢ Normal profits – optimum capacity \(Full utilisation where AC is at its minimum\) †¢ Subnormal profits – below optimum capacity \(Underutilisation where AC is falling\) Necessarily makes normal profit because of free entry and exit from the industry †¢ Supernormal profits – below optimum capacity \(Underutilisation where AC is falling\) †¢ Normal profits – below capacity \(Underutilisation where AC is falling\) †¢ Subnormal profits – below optimum capacity \(Underutilisation where AC is falling\) Can be making either normal or supernormal profits because of the presence of entry to the industry †¢ Supernormal profits – below optimum capacity \(Underutilisation where AC is falling\) †¢ Normal profits – below capacity \(Underutilisation where AC is falling\) †¢ Subnormal profits – below optimum capacity \(Underutilisation where AC is falling\) Can be making either normal or supernormal profits because of the presence of entry to the industry †¢ Supernormal profits – below optimum capacity \(Underutilisation where AC is falling\) †¢ Normal profits – below capacity \(Underutilisation where AC is falling\) †¢ Subnormal profits – below optimum capacity \(Underutilisation where AC is falling\) Plant Utilisation in SR 4 Perfect Competition Plant Utilisation in LR Normal profits – optimum capacity \(Full utilisation where AC is at its minimum\) Monopolistic Competition Normal profits – below optimum capacity \(Underutilisation where AC is falling\) Oligopoly †¢ Normal profits – below optimum capacity \(Underutilisation where AC is falling\) †¢ Supernormal profits – below optimum capacity \(Underutilisation where AC is falling\) Monopoly †¢ Normal profits – below optimum capacity \(Underutilisation where AC is falling\) †¢ Supernormal profits – below optimum capacity \(Underutilisation where AC is falling\) Allocative Efficiency Allocative efficiency is attained where P=MC Allocative efficiency is NOT attained because PMC Allocative efficiency is NOT attained because PMC Allocative efficiency is NOT attained because PMC EXCEPT when the monopolist is practising first degree \(perfect\) price discrimination Productive Efficiency \(NEW vs OLD definition\) NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is attained where profit-maximising level of output is at the minimum LRAC NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is NOT attained because profit maximising level of output is falling LRAC \(underutilisation\) NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is NOT attained because profit maximising level of output is falling LRAC \(underutilisation\) NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is NOT attained because profit maximising level of output is falling LRAC \(underutilisation\) Distinction between Firm and Industry †¢ Industry consists of many small firms producing an identical product\." A COMPARATIVE STUDY OF MARKET STRUCTURES Perfect Competition No. of Firms A large number, each being small. Monopolistic Competition A large number, each have some amount of market power. We will write a custom essay sample on Comparison Between Market Structures or any similar topic only for you Order Now Oligopoly A small number, each being mutually interdependent. Monopoly Only one firm, possessing full control in the market. Size of Firms Small. Therefore each is a price taker. Relatively small but possessing some ability in setting price. Relatively big but bases its decision on other firms. Very large and is able to influence price or output but not both simultaneously. Nature of Product Homogeneous Differentiated Differentiated Unique Knowledge of Product Perfect knowledge of market by buyers and sellers Imperfect knowledge of market by buyers and sellers Imperfect knowledge of market by buyers and sellers Imperfect knowledge of market by buyers and sellers Barriers Free entry and exit from industry Free entry and exit from industry Barriers of entry and exit from industry Barriers of entry and exit from industry Mobility of Factors Perfect Mobility Perfect Mobility Imperfect Mobility Imperfect Mobility Extent of Price Control/Pricing Policy None by individual firms who take the market prevailing price Firms may either set price or output, constrained by its demand curve Firms may either set price or output, constrained by the actions of rival firms Firms may either set price or output, constrained by its demand curve Non-price Competition No advertising or other forms of promotion because of perfect competition †¢ Perfectly price elastic – each firm is a price taker because of all the above conditions †¢ D=P=AR=MR †¢ Price is constant at all levels of output †¢ The industry’s demand and supply determine the market price Advertising and other forms of promotion may take place Advertising and other forms of promotion may take place because of price rigidity †¢ Kinked demand curve – price rigidity exists because of all the above conditions †¢ D=AR and ARMR †¢ The oligoplistic firm determines the market price or output, taking into account its competitor’s reaction No advertising or other forms of promotion because of the absence of competition †¢ Relatively price inelastic – firm is a price setter because of all the above conditions †¢ D=AR and ARMR †¢ The monopolist determines the market price or output but not both simultaneously because it is constrained by the demand curve Demand Curve/Price Line/AR curve †¢ Relatively price elastic – each firm has some ability to set price because of all the above conditions †¢ D=AR and ARMR †¢ The monopolistically competitive firm determines the market price or output but not both simultaneously because it is constrained by the demand curve 1 Perfect Competition Relationship between the demand curves of the Firm and Industry Price Price S P2 D1 D2 D0 P0 P1 AR2 AR0 AR1 Monopolistic Competition Demand Curve of the Firm $ Oligopoly Demand Curve of the Firm $ Monopoly Demand Curve of the Firm / Industry $ P2 P0 P1 MR Quantity Firm Quantity AR=DD Quantity MR AR=DD Quantity MR AR=DD Quantity Q1 Q0 Q2 Industry TR Curve †¢ TR = P x Q †¢ Because P is constant, TR curve is a linear upward-sloping from left to right Revenue Curves under Perfect Competition $ $ 60 TR †¢ TR = P x Q †¢ Because P falls when Q rises, TR curve is an inverted U-shape Revenue Curves under Monopolistic Competition $ †¢ TR = P x Q †¢ Because P falls when Q rises, TR curve is an inverted U-shape Revenue Curves under Oligopoly $ TR = P x Q †¢ Because P falls when Q rises, TR curve is an inverted U-shape Revenue Curves under Monopoly $ 10 AR=MR=DD AR=DD Quantity $ AR=DD Quantity MR Quantity 6 Quantity $ MR AR=DD Quantity $ MR TR Quantity TR Quantity TR Quantity MR Curve †¢ Identical to P and AR, that is, D=P=AR=MR †¢ Constant †¢ MR is less than AR, with the gradient of the MR curve twice as steep as the AR curve (implying that the MR cuts the quantity axis at half the length at which the AR cuts the quantity axis) †¢ Downward sloping, that is, is falling as quantity increases MR is less than AR, with the gradient of the MR curve twice as steep as the AR curve (implying that the MR cuts the quantity axis at half the length at which the AR cuts the quantity axis) †¢ Downward sloping, that is, is falling as quantity increases †¢ Presence of a broken line, implying the presence of price rigidity †¢ MR is less than AR, with the gradient of the MR curve twice as steep as the AR curve (implying that the MR cuts the quantity axis at half the length at which the AR cuts the quantity axis) †¢ Downward sloping, that is, is falling as quantity increases 2 Perfect Competition MC/AC Curves †¢ U-shaped in SR because of Law of Diminishing Returns †¢ U-shaped in LR because of internal economies and diseconomies of scale Monopolistic Competition †¢ U-shaped in SR because of Law of Diminishing Returns †¢ U-shaped in LR because of internal economies and diseconomies of scale Oligopoly †¢ U-shaped in SR because of Law of Diminishing Returns †¢ U-shaped in LR because of internal economies and diseconomies of scale Monopoly †¢ U-shaped in SR because of Law of Diminishing Returns †¢ U-shaped in LR because of internal economies and diseconomies of scale Profit-maximising Condition †¢ MR = MC where MC is rising (revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero) †¢ Since MR=P(=D=AR), when MR=MC, P=MC †¢ When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms †¢ MR = MC where MC is rising (revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero) †¢ Since PMR, when MR=MC, PMC MR = MC where MC is rising (revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equal to zero) †¢ Since PMR, when MR=MC, PMC †¢ MR = MC where MC is rising (revenue from the last unit of output is equal to the cost of producing the last unit, therefore marginal profit is equ al to zero) †¢ Since PMR, when MR=MC, PMC Meaning of SR Equilibrium †¢ When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms †¢ When individual firms no longer reshuffle output †¢ When maximum profits are attained †¢ SR equilibrium conditions are fulfilled, and †¢ No entry of new firms and no exit of existing firms Meaning of LR Equilibrium Profitability in SR †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Perfect Competition $ MC AC P0 Supernormal Profits †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Monopolistic Competition $ MC AC Supernormal Profits †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Oligopoly $ MC †¢ Supernormal profits when the firm earns profits which are in excess of what is necessary to induce it to remain in the industry Supernormal Profits under Monopoly $ MC AC Supernormal Profits AR=MR=DD P0 P0 AC Supernormal Profits P0 AR=DD MR Q0 Quantity Q0 Quantity Q0 MR AR=DD MR Quantity Q0 AR=DD Quantity 3 Perfect Competition †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Perfect Competition $ MC AC P0 AR=MR=DD Monopolistic Competition †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Monopolistic Competition $ MC AC P0 Oligopoly †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Oligopoly $ MC AC P0 Monopoly †¢ Normal profits refers to that level of profits that is just sufficient to induce the firm to stay in the industry Normal Profits under Monopoly $ MC AC P0 AR=DD MR Q0 Quantity Q0 Quantity Q0 MR AR=DD MR Quantity Q0 AR=DD Quantity †¢ Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Perfect Competition $ MC AC Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Monopolistic Competition $ AC MC Subnormal Profits †¢ Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Oligopoly $ MC AC Subnormal Profits †¢ Subnormal profits occur when the firm earns less profits than what is necessary to induce it to remain in the industry Subnormal Profits under Monopoly $ AC MC Subnormal Profits P0 Subnormal Profits AR=MR=DD P0 P0 P0 AR=DD MR Q0 Quantity Q0 Quantity Q0 MR AR=DD MR Quantity Q0 AR=DD Quantity Profitability in LR Necessarily makes normal profit because of free entry and exit from the industry †¢ Supernormal profits – beyond optimum capacity (Overutilisation where AC is rising) †¢ Normal profits – optimum capacity (Full utilisation where AC is at its minimum) †¢ Subnormal profits – below optimum capacity (Underutilisation where AC is falling) Necessarily makes normal profit because of free entry and exit from the industry †¢ Supernormal profits – below optimum capacity (Underutilisation where AC is falling) †¢ Normal profits – below capacity (Underutilisation where AC is falling) †¢ Subnormal profits – below optimum capacity (Underutilisation where AC is falling) Can be making either normal or supernormal profits because of the presence of entry to the industry †¢ Supernormal profits – below optimum capacity (Underutilisation where AC is falling) †¢ Normal profits – below capacity (Underutilisation where AC is falling) †¢ Subnormal profits – below optimum capacity (Underutilisation where AC is falling) Can be making either normal or supernormal profits because of the presence of entry to the industry †¢ Supernormal profits – below optimum capacity (Underutilisation where AC is falling) †¢ Normal profits – below capacity (Underutilisation where AC is falling) †¢ Subnormal profits – below optimum capacity (Underutilisation where AC is falling) Plant Utilisation in SR 4 Perfect Competition Plant Utilisation in LR Normal profits – optimum capacity (Full utilisation where AC is at its minimum) Monopolistic Competition Normal profits – below optimum capacity (Underutilisation where AC is falling) Oligopoly †¢ Normal profits – below optimum capacity (Underutilisation where AC is falling) †¢ Supernormal profits – below optimum capacity (Underutilisation where AC is falling) Monopoly †¢ Normal profits – below optimum capacity (Underutilisation where AC is falling) †¢ Supernormal profits – below optimum capacity (Underutilisation where AC is falling) Allocative Efficiency Allocative efficiency is attained where P=MC Allocative efficiency is NOT attained because PMC Allocative efficiency is NOT attained because PMC Allocative efficiency is NOT attained because PMC EXCEPT when the monopolist is practising first degree (perfect) price discrimination Productive Efficiency (NEW vs OLD definition) NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is attained where profit-maximising level of output is at the minimum LRAC NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is NOT attained because profit maximising level of output is falling LRAC (underutilisation) NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is NOT attained because profit maximising level of output is falling LRAC (underutilisation) NEW: Productive efficiency is attained where profit-maximising level of output is at the LRAC OLD: Productive efficiency is NOT attained because profit maximising level of output is falling LRAC (underutilisation) Distinction between Firm and Industry †¢ Industry consists of many small firms producing an identical product. Therefore, there exists a distinction between firms and industry †¢ Firm’s demand curve is perfectly elastic because it is a price taker; industry’s demand curve is downward sloping †¢ SHORT-RUN – Price ? Average Variable Cost (Total Revenue ? Total Variable Cost) †¢ LONG-RUN – Price ? Average Total Cost (Total Revenue ? Total Cost) The portion of MC curve that is above the average variable cost †¢ Industry consists of many relatively small firms producing differentiated products. Therefore, there exists a distinction between firms and industry †¢ Firm’s demand curve and the industry’s demand curve is both downward sloping Industry consists of a few large firms producing differentiated products. Therefore, there exists a distinction between firms and industry †¢ Firm’s demand curve and the industry’s demand curve is kinked implying the presence of price rigidity †¢ Industry consists of only one firm producing a unique product. Therefore, there exists NO distinction between firms and industry †¢ Firm’s demand curve is the industry’s demand curve and it is downward sloping Shut-down condition †¢ SHORT-RUN – Price ? Average Variable Cost (Total Revenue ? Total Variable Cost) †¢ LONG-RUN – Price ? Average Total Cost (Total Revenue ? Total Cost) Cannot be determined because there is no unique price to a quantity and viceversa †¢ SHORT-RUN – Price ? Average Variable Cost (Total Revenue ? Total Variable Cost) †¢ LONG-RUN – Price ? Average Total Cost (Total Revenue ? Total Cost) Cannot be determined because of the presence of price rigidity †¢ SHORT-RUN – Price ? Average Variable Cost (Total Revenue ? Total Variable Cost) †¢ LONG-RUN – Price ? Average Total Cost (Total Revenue ? Total Cost) Cannot be determined because there is no unique price to a quantity and viceversa Supply Curve in SR 5 How to cite Comparison Between Market Structures, Papers