Home building is interesting because I think a major blocker to monopoly-forming is the vastly heterogenous and complicated regulatory landscape, with building

Home building is interesting because I think a major blocker to monopoly-forming is the vastly heterogenous and complicated regulatory landscape, with building codes varying wildly from place to place. So you get a bunch of locally-specialized builders. Regulation can increase concentration in a high corruption/cronyism environment — regulatory capture and regulatory moats. There is plenty of that happening. In building, I think we have local-concentration, due to both regulatory heterogeneity and then local cronyism - Bob has decades of connections to the city and gets permits easily, whereas Bob’s competitor Steve is stuck in a loop of rejection due to a never ending list of pesky reasons.