Create table for asclogit and nlogit

You can use the cross command to generate all the possible combinations:

clear

input byte id str10 car str8 sex long income
1 "European" "Male"   45000
2 "Japanese" "Female" 48000
3 "American" "Male"   53000
end

generate choice = 0
save old, replace

keep id
save new, replace

use old
rename id =_0
cross using new

replace choice = 1 if id_0 == id
replace sex = cond(id == 2, "Female", "Male")
replace income = cond(id == 1, 45000, cond(id == 2, 48000, 53000))

Note that the use of the cond() function here is equivalent to:

replace sex = "Male"   if id == 1
replace sex = "Female" if id == 2
replace sex = "Male"   if id == 3

replace income = 45000 if id == 1
replace income = 48000 if id == 2
replace income = 53000 if id == 3

The above code snipped produces the desired output:

drop id_0
order id car choice sex income
sort id car

list, sepby(id)

     +------------------------------------------+
     | id        car   choice      sex   income |
     |------------------------------------------|
  1. |  1   American        0     Male    45000 |
  2. |  1   European        1     Male    45000 |
  3. |  1   Japanese        0     Male    45000 |
     |------------------------------------------|
  4. |  2   American        0   Female    48000 |
  5. |  2   European        0   Female    48000 |
  6. |  2   Japanese        1   Female    48000 |
     |------------------------------------------|
  7. |  3   American        1     Male    53000 |
  8. |  3   European        0     Male    53000 |
  9. |  3   Japanese        0     Male    53000 |
     +------------------------------------------+

For more information, type help cross and help cond() from Stata's command prompt.