random selection between observation

[Mehdi Amani]

Hi everyone,
In the below dataset, I want to randomly delete one of the observations that has the same wage for a given year. For example, I would be happy if Stata randomly drops business a or b for year 93. Do you have any idea?
thanks a lot.

year	wage	business
93	100	a
93	100	b
94	150	c
95	200	d
95	250	e
96	300	f

[Joseph Coveney]

set seed 357993207                     // <= important
generate double randu = runiform()
isid randu                             // <= also important if large dataset
bysort year wage (randu): keep if _n == 1

alternatively

set seed 928467163
generate double randu = runiform()
isid year wage randu, sort
by year wage:  keep if _n == 1

[Mehdi Amani]

Thank you so much. Another question. For example, Iook at the table below. in the 93, because I have same wage for same year, I would like to drop the observation which individual didn't work in the previous year. I mean, I want to keep a business obs for the 93. But for the 94, it should be random as it was before.
many thanks.

year	wage	business
92	100	a
93	150	a
93	150	b
94	200	c
94	200	d
94	200	h
95	300	e
96	350	f
96	400	g