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In this example, a multiple regression model is fitted using program quality ratings (QUALITY) as the regressand/outcome variable and number of published articles attributed to the program faculty members (NARTIC), percent of faculty members holding research grants (PCTGRT), and percentage of program graduates who received support (PCTSUPP) as regressor/predictor variables using a data set from 1982 ratings of 46 doctoral programs in psychology in the USA (National Research Council, 1982). Confidence intervals for the standardized regression coefficients are generated using the BetaMC() function from the betaMC package.

df <- betaMC::nas1982

Regression

Fit the regression model using the lm() function.

object <- lm(QUALITY ~ NARTIC + PCTGRT + PCTSUPP, data = df)

Monte Carlo Sampling Distribution of Parameters

Normal-Theory Approach

mvn <- MC(object, type = "mvn")

Asymptotic distribution-free Approach

adf <- MC(object, type = "adf")

Heteroskedasticity Consistent Approach (HC3)

hc3 <- MC(object, type = "hc3")

Standardized Regression Slopes

Normal-Theory Approach

mvn <- BetaMC(mvn)

Asymptotic distribution-free Approach

adf <- BetaMC(adf)

Heteroskedasticity Consistent Approach (HC3)

hc3 <- BetaMC(hc3)

Methods

summary

Summary of the results of BetaMC().

summary(mvn)
#> Call:
#> BetaMC(object = mvn)
#> 
#> Standardized regression slopes
#> type = "mvn"
#>            est     se     R  0.05%   0.5%   2.5%  97.5%  99.5% 99.95%
#> NARTIC  0.4951 0.0757 20000 0.2505 0.2922 0.3388 0.6335 0.6806 0.7295
#> PCTGRT  0.3915 0.0769 20000 0.1443 0.1934 0.2379 0.5399 0.5906 0.6539
#> PCTSUPP 0.2632 0.0749 20000 0.0296 0.0791 0.1171 0.4125 0.4593 0.5091
summary(adf)
#> Call:
#> BetaMC(object = adf)
#> 
#> Standardized regression slopes
#> type = "adf"
#>            est     se     R  0.05%   0.5%   2.5%  97.5%  99.5% 99.95%
#> NARTIC  0.4951 0.0676 20000 0.2581 0.3091 0.3518 0.6158 0.6558 0.6931
#> PCTGRT  0.3915 0.0711 20000 0.1283 0.1942 0.2411 0.5188 0.5575 0.6031
#> PCTSUPP 0.2632 0.0768 20000 0.0136 0.0596 0.1084 0.4085 0.4548 0.5068
summary(hc3)
#> Call:
#> BetaMC(object = hc3)
#> 
#> Standardized regression slopes
#> type = "hc3"
#>            est     se     R   0.05%   0.5%   2.5%  97.5%  99.5% 99.95%
#> NARTIC  0.4951 0.0794 20000  0.2111 0.2706 0.3227 0.6340 0.6743 0.7262
#> PCTGRT  0.3915 0.0825 20000  0.0956 0.1568 0.2149 0.5386 0.5834 0.6322
#> PCTSUPP 0.2632 0.0855 20000 -0.0333 0.0281 0.0890 0.4278 0.4782 0.5478

coef

Return the vector of estimates.

coef(mvn)
#>    NARTIC    PCTGRT   PCTSUPP 
#> 0.4951451 0.3914887 0.2632477
coef(adf)
#>    NARTIC    PCTGRT   PCTSUPP 
#> 0.4951451 0.3914887 0.2632477
coef(hc3)
#>    NARTIC    PCTGRT   PCTSUPP 
#> 0.4951451 0.3914887 0.2632477

vcov

Return the sampling covariance matrix.

vcov(mvn)
#>               NARTIC       PCTGRT     PCTSUPP
#> NARTIC   0.005728673 -0.003274517 -0.00217137
#> PCTGRT  -0.003274517  0.005910844 -0.00172188
#> PCTSUPP -0.002171370 -0.001721880  0.00560837
vcov(adf)
#>               NARTIC       PCTGRT      PCTSUPP
#> NARTIC   0.004575329 -0.002529996 -0.001687205
#> PCTGRT  -0.002529996  0.005059420 -0.001914164
#> PCTSUPP -0.001687205 -0.001914164  0.005892514
vcov(hc3)
#>               NARTIC       PCTGRT      PCTSUPP
#> NARTIC   0.006310814 -0.003616011 -0.001986759
#> PCTGRT  -0.003616011  0.006805482 -0.002311942
#> PCTSUPP -0.001986759 -0.002311942  0.007317821

confint

Return confidence intervals.

confint(mvn, level = 0.95)
#>             2.5 %    97.5 %
#> NARTIC  0.3387912 0.6334927
#> PCTGRT  0.2379335 0.5399119
#> PCTSUPP 0.1171396 0.4124892
confint(adf, level = 0.95)
#>             2.5 %    97.5 %
#> NARTIC  0.3518445 0.6157971
#> PCTGRT  0.2411247 0.5187594
#> PCTSUPP 0.1084217 0.4084592
confint(hc3, level = 0.95)
#>              2.5 %    97.5 %
#> NARTIC  0.32267000 0.6340454
#> PCTGRT  0.21488495 0.5386319
#> PCTSUPP 0.08897104 0.4278247

References

Dudgeon, P. (2017). Some improvements in confidence intervals for standardized regression coefficients. Psychometrika, 82(4), 928–951. https://doi.org/10.1007/s11336-017-9563-z
National Research Council. (1982). An assessment of research-doctorate programs in the United States: Social and behavioral sciences. National Academies Press. https://doi.org/10.17226/9781
Pesigan, I. J. A., & Cheung, S. F. (2023). Monte Carlo confidence intervals for the indirect effect with missing data. Behavior Research Methods, 56(3), 1678–1696. https://doi.org/10.3758/s13428-023-02114-4