EV CARP

EV CARP is a program for regression analysis of data containing measurement error in the explanatory variables. Computations can be carried out for four basic models, where the four models are:

• Weighted Least Squares

  Estimates of regression parameters computed using weights supplied with data.

  EV1

  Estimate of regression parameters computed under assumption that error covariances associated with explanatory variables are known, or estimated from an external source. Error covariances are part of program input.

  EV2

  Estimates of regression parameters computed under assumption that the reliability ratios of the explanatory variables are known, or estimated from an external source. Reliability ratios are part of the program input.

  EV3

  Estimates of regression parameters computed under assumption that the error covariance matrix for entire vector is known, or estimated from an external source. Error covariance matrix is part of the program input.

Several options are available for each of the basic procedures. In particular, the covariance matrix of the estimator can be constructed using the assumption of normal errors, or using a distribution-free procedure based on the Taylor expansion of the estimator. The Taylor option permits one to correctly estimate the covariance matrix of the estimators for data collected by multistage stratified survey designs. Weights can also be used in the computations.

Additional options permit the user to obtain residuals, to estimate the values of the variables measured with error, and to perform tests on the coefficients. An option is also available for measurement error variances that vary by observation.

The program will accept 49 variables. There is no limit on the number of observations.

EV CARP is designed for the IBM Personal Computer, IBM PC/XT, or IBM PC/AT. EV CARP for the PC/AT is transported on a high-density diskette. The program requires 450K of memory and the machine should have 512K of memory to run the program. The personal computer must have a math coprocessor (8087, 80287, or similar). If the machine does not have a math coprocessor, loading the program will produce the error message "Error in EVCARP Error number 4001."

Cost of the CARP software is as follows:

    PC CARP for PC (MS-DOS)...................$300.00

    Logistic supplement (PC CARPL).............$50.00

    Post Stratification supplement (POST CARP).$50.00

    EV CARP for PC (MS-DOS)...................$300.00

    PC CARP and EV CARP for PC (MS-DOS).......$500.00

    SUPER CARP (Main Frame program)...........$150.00

        Additional PC CARP manuals @$8.00
        Additional EV CARP manuals @$8.00
        Additional SUPER CARP manuals @$8.00

Download a PDF version of the order form.

EV CARP can be obtained by contacting:

Sandie Smith
Center for Survey Statistics & Methodology
219 Snedecor Hall
Ames, IA 50011

phone: 515/294-9773
FAX: 515/294-4433
 
e-mail: sandie@iastate.edu