The aim of government must therefore be to design tax policy in the most efficient and effective way possible, to bring maximum benefits at minimum cost.
Rhaid i’r llywodraeth, felly, anelu at gynllunio polisi treth yn y modd mwyaf effeithlon ac effeithiol sy’n bosibl, er mwyn creu’r buddiannau mwyaf am y gost isaf.