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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 0.0759 20000 0.2234 0.2874 0.3381 0.6340 0.6761 0.7226
#> PCTGRT  0.3915 0.0772 20000 0.1399 0.1925 0.2390 0.5411 0.5877 0.6551
#> PCTSUPP 0.2632 0.0743 20000 0.0236 0.0690 0.1174 0.4099 0.4565 0.5174
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 0.2564 0.3066 0.3513 0.6142 0.6538 0.6957
#> PCTGRT  0.3915 0.0707 20000 0.1444 0.2017 0.2428 0.5208 0.5623 0.6087
#> PCTSUPP 0.2632 0.0772 20000 0.0014 0.0564 0.1041 0.4102 0.4572 0.5080
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 0.0796 20000  0.2003 0.2683 0.3251 0.6375 0.6783 0.7215
#> PCTGRT  0.3915 0.0820 20000  0.0881 0.1614 0.2191 0.5388 0.5871 0.6355
#> PCTSUPP 0.2632 0.0856 20000 -0.0211 0.0369 0.0904 0.4277 0.4814 0.5438

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   0.005762470 -0.003319023 -0.002120623
#> PCTGRT  -0.003319023  0.005954144 -0.001718859
#> PCTSUPP -0.002120623 -0.001718859  0.005522013
vcov(adf)
#>               NARTIC       PCTGRT      PCTSUPP
#> NARTIC   0.004565231 -0.002499484 -0.001729370
#> PCTGRT  -0.002499484  0.004995033 -0.001865171
#> PCTSUPP -0.001729370 -0.001865171  0.005959984
vcov(hc3)
#>               NARTIC       PCTGRT      PCTSUPP
#> NARTIC   0.006343733 -0.003514731 -0.002019547
#> PCTGRT  -0.003514731  0.006724430 -0.002388766
#> PCTSUPP -0.002019547 -0.002388766  0.007326845

confint

Return confidence intervals.

confint(mvn, level = 0.95)
#>             2.5 %    97.5 %
#> NARTIC  0.3381424 0.6340365
#> PCTGRT  0.2390118 0.5411024
#> PCTSUPP 0.1174013 0.4099336
confint(adf, level = 0.95)
#>             2.5 %    97.5 %
#> NARTIC  0.3512526 0.6141536
#> PCTGRT  0.2427981 0.5208196
#> PCTSUPP 0.1041002 0.4102236
confint(hc3, level = 0.95)
#>              2.5 %    97.5 %
#> NARTIC  0.32510763 0.6374914
#> PCTGRT  0.21914605 0.5387558
#> PCTSUPP 0.09041618 0.4277101

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. https://doi.org/10.3758/s13428-023-02114-4