N. Gregory Mankiw
His economic beliefs were influenced by John Maynard Keynes and he believes in Keynesian economics.  He is sometimes labeled as a conservative because he supported George W. Bush's tax cuts and he has criticized the policies of the Obama Administration a few times.  He also was influenced by the economist Arthur Pigou who believed that a high tax on something bad for society (called a sin tax) will result in fewer people buying it.