Returns to scale - Wikipedia
In this lesson, we'll learn about constant returns to scale. Marginal Product of Labor: Definition, Formula & Example . Constant returns to scale is used to describe the relationship between the amount of I am a teacher . Services Marketing: The Difference Between Services and Goods ; How. In economics, returns to scale and economies of scale are related but different concepts that describe While economies of scale show the effect of an increased output level on unit costs, returns to scale focus only on the relation between. The aim of this lesson is to present ''returns to scale'' as it is used in an economic context. She has 14 years of experience as a classroom teacher, and several years in both The lesson will provide a definition of key terms, as well as some cause and effect relationships. .. What best describes you?.
Uses relevant and accurate evidence to weigh the advantages and disadvantages of multiple option, and makes a choice supported by the evidence.
Returns to scale
Missing, illegible, or completely lacks reasons and evidence. X Student had no opportunity to respond. Science Education for Public Understanding Program Page 69 Share Cite Suggested Citation: Keyed to standards and goals, such systems can be strong on meaning for teachers and students and still convey information to different levels of the system in a relatively straightforward and plausible manner that is readily understood.
Teachers can use the standards or goals to help guide their own classroom assessments and observations and also to help them support work or learning in a particular area where sufficient achievement has not been met. Devising a criterion-based scale to record progress and make summative judgments poses difficulties of its own.
The levels of specificity involved in subdividing a domain to assure that the separate elements together represent the whole is a crucial and demanding task Wiliam, This becomes an issue whether considering performance assessments or ongoing assessment data and needs to be articulated in advance of when students engage in activities Quellmalz, ; Gipps, Specific guidelines for the construction and selection of test items are not offered in this document.
Test design and selection are certainly important aspects of a teacher's assessment responsibility and can be informed by the guidelines and discussions presented in this document see also Chapter 3. Item-writing recommendations and other test specifications are topics of a substantial body of existing literature for practitioner-relevant discussions, see Airasian, ; Cangelosi, ; Cunningham, ; Doran, Chan, and Tamir, ; Gallagher, ; Gronlund, ; Stiggins, These concepts also are discussed in Chapter 3.
Validity and reliability are judged using different criteria, although the two are related. It is important to consider the uses of assessment and the appropriateness of resulting inferences and actions as well Messick, Reliability has to do with generalizing across tasks is this a generalizable measure of student performance?
What these terms mean operationally varies slightly for the kinds of assessments that occur each day in the classroom and in the form of externally designed exams. The dynamic nature of day-to-day teaching affords teachers with opportunities to make numerous assessments, take relevant action, and to amend decisions and evaluations if necessary and with time. With a single-test score, especially from a test administered at the end of the school year, a teacher does not have the opportunity to follow a response with another question, either to determine if the previous question had been misinterpreted or to probe misunderstandings for diagnostic reasons.
With a standardized test, where on-the-spot interpretation of the student's response by the teacher and follow-up action is impossible, the context in which responses are developed is ignored. Measures of validity are decontextualized, depending almost entirely on the collection and nature of the actual test items. More important, all users of assessment data teachers, administrators and policy makers need to be aware of what claims they make about a student's understanding and the consequential action based on any one assessment.
Relying on a variety of assessments, in both form and what is being assessed, will go a long way to ensuring validity. Much of what is called for in the standards, such as inquiry, cannot be assessed in many of the multiplechoice, short-answer, or even two-hour performance assessments that are currently employed.
Reliability, though more straightforward, may be more difficult to ensure than validity. Viable systems that command the same confidence as the current summative system but are free of many of the inherent conflicts and contradictions are necessary to make decisions psychometrically sound.
The confidence that any assessment can demand will depend, in large part, on both reliability and validity Baron, ; Black, As Box indicates, there are some basic questions to be asked of both teacher-made and published assessments. Teachers need to consider the technical aspect of the summative assessments they use in the classroom.
They also should look for evidence that disproves earlier judgments and make necessary accommodations. Economies of scale are most likely to be found in industries with large fixed costs in production. Fixed costs are those costs that must be incurred even if production were to drop to zero. For example, fixed costs arise when large amounts of capital equipment must be put into place even if only one unit is to be produced and if the costs of this equipment must still be paid even with zero output.
In this case, the larger the output, the more the costs of this equipment can be spread out among more units of the good. Large fixed costs and hence economies of scale are prevalent in highly capital-intensive industries such as chemicals, petroleum, steel, automobiles, and so on.
Decreasing returns to scale | Economics Help
Economies of Scale and Perfect Competition It is worth noting that the assumption of economies of scale in production can represent a deviation from the assumption of perfectly competitive markets. In most perfectly competitive models, it is assumed that production takes place with constant returns to scale i. This means that the unit cost of production remains constant as the scale of production increases.
When that assumption is changed, it can open up the possibility of positive profits and strategic behavior among firms. Because there are numerous ways to conceive of strategic interactions between firms, there are also numerous models and results that could be obtained. To avoid some of these problems, a number of models have been developed that retain some of the key features of perfect competition while allowing for the presence of economies of scale as well.
Key Takeaways Economies of scale refers to the feature of many production processes in which the per-unit cost of producing a product falls as the scale of production rises. Increasing returns to scale refers to the feature of many production processes in which productivity per unit of labor rises as the scale of production rises.
The introduction of economies of scale in production in a model is a deviation from perfect competition when positive economic profits are allowed to prevail. As in the popular television game show, you are given an answer to a question and you must respond with the question. The assumption about scale economies normally made in perfect competition.
The term used to describe total production costs per unit of output.