He was interested in property rights, applied price theory, and political economy.
Barzel is known for developing a property rights/transaction cost approach to economics and he has written on topics ranging from car racing to slavery, to Jewish lending to voting rules in condominium associations.
In the process Barzel's work unearthed the economic rationale for many institutions and offered a framework for analyzing them.
Barzel holds an important place among all economists for expanding the scope of economic science in a way that focuses attention on the importance of institutions and the economic logic of their variety.
He took a lot from discussions with his fellow mate at Seattle, Steven N. S. Cheung, but both were not sharing the same opinion about the/their master, Ronald H. Coase.