What do we call the variable that the scientist changes first

i do agree with robert moses’ statements about wiping out cities that are an “impediment to new growth”. in order to have a positive community, the city must continue to grow either in terms of size or economics. therefore wiping out cities that restrict growth benefits the overall society and all the people living in it. similar to a social contract, i believe that if a person was to live in a community they must sacrifice some of their rights, in this case property, for the overall good of the people. as long as these people living in the cities are reimbursed and the purpose of wiping out the cities is to serve the public, there is no problem with robert moses’ core idea.