This from the Institue of Fical Studies reacting to the Lib Dems election announcements on taxation.

The LibDems have responded with this:

"Rather than making people fill out complex forms to get benefits only to tax them through the nose, Liberal Democrats believe people on low and middle incomes should simply be allowed to keep more of their own money." That's the Lib Dem response to criticism by the Institute for Fiscal Studies. The IFS said their claims on tax ignored the effect of the benefits system in helping the UK's poorest, but the party said the think tank's analysis only "serves to further highlight the absurd tax and benefits system created by Gordon Brown".

I have not studied this issue enough, but my initial feeling is how can the LibDems position on this be the wrong one?