<prompt> Translate the following text to EnglishWakati elasticities msalaba ni sifuri, faida kubwa ustawi ni inapatikana kutoka punguzo kubwa kuliko 6a na punguzo bora inaonekana kuwa juu sana ya 8a.  <response>: When the cross elasticities are zero, substantial welfare gains are available from discounts larger than 6a and the optimal discount appears to be well above 8a. 