Import Data

library(lavaan)
## This is lavaan 0.6-13
## lavaan is FREE software! Please report any bugs.
estress <- read.csv("estress.csv")
head(estress)
##   tenure estress affect withdraw sex age  ese
## 1   1.67     6.0   2.60     3.00   1  51 5.33
## 2   0.58     5.0   1.00     1.00   0  45 6.05
## 3   0.58     5.5   2.40     3.66   1  42 5.26
## 4   2.00     3.0   1.16     4.66   1  50 4.35
## 5   5.00     4.5   1.00     4.33   1  48 4.86
## 6   9.00     6.0   1.50     3.00   1  48 5.05

Model

withdraw_model <- "
affect ~ a_ag * age + a_se * sex + a_es * estress
withdraw ~ age + sex + estress + b * affect
c_es := a_es * b"
withdraw_model
## [1] "\naffect ~ a_ag * age + a_se * sex + a_es * estress\nwithdraw ~ age + sex + estress + b * affect\nc_es := a_es * b"

Means

colMeans(estress)
##     tenure    estress     affect   withdraw        sex        age        ese 
##  5.9285878  4.6202290  1.5980916  2.3211450  0.6183206 43.7938931  5.6073282

Correlation Matrix

estresscorrelation <-cor(estress)
estresscorrelation
##                tenure     estress      affect    withdraw          sex
## tenure    1.000000000  0.06787622 -0.06520633 -0.03536860 -0.003181564
## estress   0.067876218  1.00000000  0.34006259  0.06407186  0.132833014
## affect   -0.065206327  0.34006259  1.00000000  0.41658602  0.046217575
## withdraw -0.035368601  0.06407186  0.41658602  1.00000000  0.050029219
## sex      -0.003181564  0.13283301  0.04621758  0.05002922  1.000000000
## age       0.266195837  0.06598494 -0.01779056 -0.03526418  0.083119846
## ese      -0.060421582 -0.15826688 -0.24552431 -0.24250778  0.028105987
##                  age         ese
## tenure    0.26619584 -0.06042158
## estress   0.06598494 -0.15826688
## affect   -0.01779056 -0.24552431
## withdraw -0.03526418 -0.24250778
## sex       0.08311985  0.02810599
## age       1.00000000 -0.08263488
## ese      -0.08263488  1.00000000

Standard Deviations

sapply(estress[,2:6], sd)
##    estress     affect   withdraw        sex        age 
##  1.4236142  0.7237171  1.2468702  0.4867283 10.3596014

Sem Model

estressfit_mod <- sem (
  model = withdraw_model, data = estress,
  se = "bootstrap", bootstrap = 5000)
estressfit_mod
## lavaan 0.6.13 ended normally after 1 iteration
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                         9
## 
##   Number of observations                           262
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
summary(estressfit_mod, standardize = TRUE, rsquare = TRUE, ci = TRUE)
## lavaan 0.6.13 ended normally after 1 iteration
## 
##   Estimator                                         ML
##   Optimization method                           NLMINB
##   Number of model parameters                         9
## 
##   Number of observations                           262
## 
## Model Test User Model:
##                                                       
##   Test statistic                                 0.000
##   Degrees of freedom                                 0
## 
## Parameter Estimates:
## 
##   Standard errors                            Bootstrap
##   Number of requested bootstrap draws             5000
##   Number of successful bootstrap draws            5000
## 
## Regressions:
##                    Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##   affect ~                                                              
##     age     (a_ag)   -0.003    0.005   -0.602    0.547   -0.012    0.006
##     sex     (a_se)    0.006    0.094    0.066    0.948   -0.182    0.192
##     estress (a_es)    0.174    0.042    4.188    0.000    0.089    0.251
##   withdraw ~                                                            
##     age              -0.003    0.007   -0.434    0.664   -0.016    0.011
##     sex               0.112    0.148    0.758    0.448   -0.177    0.389
##     estress          -0.080    0.055   -1.470    0.142   -0.186    0.030
##     affect     (b)    0.767    0.142    5.420    0.000    0.493    1.043
##    Std.lv  Std.all
##                   
##    -0.003   -0.041
##     0.006    0.004
##     0.174    0.342
##                   
##    -0.003   -0.025
##     0.112    0.044
##    -0.080   -0.091
##     0.767    0.445
## 
## Variances:
##                    Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##    .affect            0.461    0.082    5.637    0.000    0.311    0.625
##    .withdraw          1.266    0.096   13.242    0.000    1.053    1.430
##    Std.lv  Std.all
##     0.461    0.883
##     1.266    0.817
## 
## R-Square:
##                    Estimate
##     affect            0.117
##     withdraw          0.183
## 
## Defined Parameters:
##                    Estimate  Std.Err  z-value  P(>|z|) ci.lower ci.upper
##     c_es              0.133    0.033    3.983    0.000    0.071    0.202
##    Std.lv  Std.all
##     0.133    0.152

Plot Path Diagram

library(lavaanPlot)
lavaanPlot(
  model = estressfit_mod, coefs = TRUE, covs = TRUE,
  stars = "regress", stand = TRUE)

Write-Up

Path analysis was used to test the withdrawal model based on data from 262 people. We used lavaan version 0.6.13 (Rosseel, 2012), with maximum likelihood estimation. The variables of age (b = -0.003, se = 0.005, p = 0.535) and sex (b = 0.006, se = 0.094, p = 0.948) were not found to be statistically significant predictors of depressive affect. However, economic stress (b = 0.174, se = 0.042, p = 0.000) is a statistically significant predictor of depressive affect. Depressive affect (b = 0.767, se = 0.141, p = 0.000) was found to be the only statistically significant predictor of withdrawal intentions. The variables of age (b = -0.003, se = 0.007, p = 0.660), sex (b = 0.112, se = 0.146, p = 0.765), and economic stress (b = -0.080, se = 0.055, p = 0.145) were not statistically significant predictors of withdrawal intentions. There is evidence to suggest an indirect effect of economic stress to withdrawal intentions mediated by depressive affect.