Allan T. Ingraham (Criterion Auctions) & J. Gregory Sidak (American Enterprise Institute) have published Do States Tax Wireless Services Inefficiently?  Evidence on the Price Elasticity of Demand, 24 Va. Tax Rev. 249 (2004).  Here is the Conclusion:

The distortionary effects of an ad valorem tax on wireless services vary inversely with the own-price elasticity of demand for wireless services. Although the demand for wireless service has become more elastic over the last decade, wireless taxes have increased. Consequently, the efficiency loss from wireless taxation has also risen during that period. In states that tax wireless services most aggressively, the efficiency loss from an additional dollar of tax revenue raised may be as high as two dollars. Therefore, federal, local, and state governments should carefully scrutinize the tax rates they currently impose on wireless consumers, recognizing that the tax policies in place can produce more harm than good.