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

Determine the objectives of ratio analysis, Objectives of ratio analysis ...

Objectives of ratio analysis 1) Measuring the profitability: we can measure the profitability of the business by calculation gross profit net profit expenses ratio and other.

Determine the internal factors of pricing decision, Determine the Internal ...

Determine the Internal factors of pricing decision 1) Organization factor: pricing decision occur on two level in the organization. Overall price strategy is dealt with by to

Capital budgeting – planning investments, The management of Popular Stores ...

The management of Popular Stores Sdn. Bhd. are in the process of exploring the company’s investment opportunities.

Electronic fund transfer, By electronic fund transfer the collection float ...

By electronic fund transfer the collection float can be completely removed the other benefit of electronic fund transfer is instant updating of accounts and reporting of balances a

State the target pricing method, Rate of return or target pricing method ...

Rate of return or target pricing method Under this method of price determination first of all a rate of return desired by the enterprises on the amount of profit capital inves

Cvp analysis and computer applications, CVP ANALYSIS AND COMPUTER APPLICATI...

CVP ANALYSIS AND COMPUTER APPLICATIONS The output from a CVP model is only as good as the input. The analysis will include assumptions about sales mix, production efficiency, p

Case law & study, You are charged with describing the important considerati...

You are charged with describing the important considerations in the decision-making process to upper management. In your response, be sure to include the following: • A descript

Bench marking, BENCH MARKING In the current business environment, organ...

BENCH MARKING In the current business environment, organizations are under a lot of pressure to improve performance and that of their divisions or subsidiaries. Bench marking i

Cost, What are the limation of semi variable cost and how to overcome it?

What are the limation of semi variable cost and how to overcome it?

Markov properties, Markov Properties 1) Transition probabilities are de...

Markov Properties 1) Transition probabilities are dependent only on the current state of the system i.e. provided that the current state is recognized; the conditional probabil

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