Railways and rent

So far we have twelve estates with kilometres of railway track counted up. In the regression we get very satisfactory results, which go to show that railway construction did indeed cut costs for farmers---but those savings were transferred to their landlords in the form of higher rents. However, in my readings I am finding some interesting differences between landlords. Some landlords had political ambitions and wished to be able to direct the votes of their tenants. As a result they under-rented...so the next research step is to try to find out which of our landlords had political ambitions, and then include this variable as a dummy variable. Then we can see the effect of politics on rent.