Summary Function showing NA in Results but data doesn't have missing values

[DatAnnihilyst]

As stated above. I ran a multiple regression model and used the summary function. Would like to know what NA means in results. No data is missing at all. There are 89 variables but only showing a few below.

Call:
lm(formula = Gross.Monthly.Income ~ ., data = Member_Income_Data_Draft)

Residuals:
Min 1Q Median 3Q Max
-1358313 -82138 -16520 39568 24442058

Coefficients: (10 not defined because of singularities)
Estimate Std. Error t value Pr(>|t|)
(Intercept) -3.840e+04 2.983e+05 -0.129 0.89755
Auto.Loan 7.999e+04 1.305e+04 6.127 9.21e-10 ***
Credit.Card -2.155e+03 7.953e+03 -0.271 0.78638
Gender -3.772e+04 6.848e+03 -5.509 3.68e-08 ***
Income.Level -5.360e+03 4.739e+04 -0.113 0.90996
DIVORCED 5.446e+04 5.924e+04 0.919 0.35791
MARRIED 4.659e+04 5.447e+04 0.855 0.39242
MISSING_MAR_STAT 2.376e+04 8.168e+04 0.291 0.77111
OTHER_MAR_STAT 1.503e+04 6.809e+04 0.221 0.82531
UNMARRIED 6.687e+03 5.451e+04 0.123 0.90237
WIDOWED NA NA NA NA
REG_CUST_CLASS NA NA NA NA

Signif. codes: 0 ‘’ 0.001 ‘’ 0.01 ‘’ 0.05 ‘.’ 0.1 ‘ ’ 1

Residual standard error: 364900 on 12376 degrees of freedom
Multiple R-squared: 0.1515, Adjusted R-squared: 0.1461
F-statistic: 28.33 on 78 and 12376 DF, p-value: < 2.2e-16

[nirgrahamuk]

It means you have correlated inputs.
For example:

mydata <- data.frame(
  g=c(rep("a",5),rep("b",5)),
  target=1:10,
  useful_input = -(1:10) + rnorm(10,0,1)
)
lm(target ~ . , data=mydata) %>% summary

mydata2 <- mydata
mydata2$trouble <- mydata$useful_input/2

lm(target ~ . , data=mydata2) %>% summary

[arthur.t]

WIDOWED NA NA NA NA
REG_CUST_CLASS NA NA NA NA

Plot WIDOWED against REG_CUST_CLASS to see if you can identify the issue. Some of your variables are perfectly multicollinear and the next step is to identify how, and address by removing a variable, or engineering a new feature to replace the problematic one(s).

[DatAnnihilyst]

Thank you @nirgrahamuk @arthur.t I checked and found some which were correlated.

Much appreciated, cheers!