Salience and Taxation.

Chetty et al. (2009)
Raj Chetty,Adam Looney,Kory Kroft
Summary by 
Mark Egan

A field experiment conducted in stores in California tested whether purchasing behavior was affected when prices for some goods were raised at the till or on the price-tag. The authors found that tax-inclusive price tags reduced demand by 8%, likely due to them being much more salient whereas being charged later at the till had no significant effect on purchase behaviour.