<prompt> Translate the following text to SwahiliWhen 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.  <response>: Wakati elasticities msalaba ni sifuri, faida kubwa ustawi ni inapatikana kutoka punguzo kubwa kuliko 6a na punguzo bora inaonekana kuwa juu sana ya 8a. 