How are Realtors maintaining their cartel (even) in the internet age?

A new NBER paper sheds some light on Realtors...

Conflicts of Interest and the Realtor Commission Puzzle

Panle Jia Barwick, Parag A. Pathak, Maisy Wong

NBER Working Paper No. 21489
Issued in August 2015

This paper documents uniformity in real estate commission rates across markets and time using a dataset on realtor commissions for 653,475 residential listings in eastern Massachusetts from 1998-2011. Newly established real estate brokerage offices charging low commissions grow more slowly than comparable entrants with higher commissions. Properties listed with lower commission rates experience less favorable transaction outcomes: they are 5% less likely to sell and take 12% longer to sell. These adverse outcomes reflect decreased willingness of buyers' agents to intermediate low commission properties (steering) rather than heterogeneous seller preferences or reduced effort of listing agents. While all agents and offices prefer properties with high commissions, firms and agents with large market shares purchase a disproportionately small fraction of low commission properties. The negative outcomes for low commissions provide empirical support for regulatory concerns that steering reinforces the uniformity of commissions.