st: How can I assess relative importance of two coefficients in an equation?

["Dr. Stephen Owusu-Ansah" <sowusuansah@rgv.rr.com>]

Dear Colleagues:

How can I assess the relative importance of two coefficients using Wald 
test? Thus, I want toi test a null hypothesis that the explanatory 
powers of X_3 and X_4 of the following equation are equal by comparing 
their Wald chi-square statistic:

Y = b1 + b2X_1 + b3X_2 + b4X_3 + b5X_4.

If I use the "test" command after estimation, the results reported by 
Stata is in F-distribution, but I want the results to be reported in 
chi-square distribution with its associated p-value.

Is there any ado for this test? Can somebody help me to write the code 
if it doesn't already exist?

Regards,

Stephen

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