Independence of observations, Managerial Accounting

Assignment Help:

Independence of observations

An important assumption for the simple linear regression model is the independence of errors. In many time series models, this assumption is violated because of the correlation of errors in successive observations. This is termed to as autocorrelation.

Autocorrelation occurs if a positive error is followed by another positive error and a negative error is followed by another negative error. If autocorrelation occurs then time should be considered as an important independent variable and therefore time varies analysis should be used.

We can use Durbin Watson ‘D’ statistics to determine whether observations are independent.
D = ∑(ei – ei-1)2
        ∑ei2

Where:

ei is the error in time i
ei-I is the error in time i-I

The Durbin Watson statistics provides a measure of association between successive values of the error term. The computed statistics is compared against two tabulated values du and dl that depend on the desired confidence level of the test and the degrees of freedom of the data.

If the computed Durbin Watson “D” statistics is greater than Du, then we can conclude that there’s no positive correlation between error terms.

If dl ≤ D≤ du then the test is inconclusive and therefore we can neither accept nor reject the null hypothesis.


Related Discussions:- Independence of observations

Calculate the overall profit if the offer is accepted, Question : (a) ...

Question : (a) A company manufactures and sells two products A and B. Presently, it sells 600 units of A and 400 units of B at a price of £24 and £19 respectively. The unit

Implied interest rate, Suppose the spot price of gold is $1700 per ounce. T...

Suppose the spot price of gold is $1700 per ounce. The futures price for delivery in six months is $1712, while the futures price for delivery in one year is $1720. The interest ra

What is the responsibility of operating budget, What is the Responsibility ...

What is the Responsibility of operating budget when the operating budget of a firm is constructed in terms of responsibility areas it is called the responsibility budget shows

Job order costing, Prepare Summary Journal Entries to record the( 1) requi...

Prepare Summary Journal Entries to record the( 1) requistion slips

Planning, Planning A business must plan for its success. What do w...

Planning A business must plan for its success. What do we understand by business planning? It is about thinking in advance -- to decide on a course of the action to reach

Management, Discuss the different roles played by the qualitative and quant...

Discuss the different roles played by the qualitative and quantitative approaches to managerial decision making

Explain the mark up pricing, Full cost or mark up pricing or cost plus pric...

Full cost or mark up pricing or cost plus pricing method: In this method the marketer estimates the total cost of producing or manufacturing the product and then adds it a mar

Profi t Planning, SK 2 Chapter 10: Master budgeting Objective How organisat...

SK 2 Chapter 10: Master budgeting Objective How organisations strive to achieve their financial goals by preparing a number of budgets that together form an integrated business pla

Rules of game theory, RULES OF GAME THEORY 1) The number of competitors...

RULES OF GAME THEORY 1) The number of competitors is finite. 2) There is a conflict of interests between the participants. 3) Each of these participants has available to

Define case study of orion financial management, Case study of Orion Financ...

Case study of Orion Financial Management - Portfolio Management? Maria Gilbert is a principal in the company of Orion Financial Management. For 20 years she was chief investm

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd