The authors analyse the development of migration policies. They construct an index of immigration policy to assess changes of policy over time for 1860-1930. The focus on five countries of immigration-Australia, Argentina, Brazil, Canada, and the United States.
Based on policy change (changes in the index were introduced only when policy changed), the index ranges over a scale of +5 to -5. A positive score denotes a pro-immigration policy A negative score denotes anti-immigration policy, A zero denotes policy neutrality, or a neutral outcome between conflicting pro- and anti-immigration policies.