Problem $4.($Institutions$).$ Acemoglu, Johnson, and Robinson explore the relationship between property rights and economic development. The authors present three correlations in the data on former colonies: $($a$)$ The correlation between property rights in $1995$ and GDP in $1995$ is positive; $($b$)$ the correlation between good property rights in $1995$ and settler mortality is negative; and $($c$)$ the correlation between GDP in $1995$ and settler mortality is negative. Explain how could these correlations be used to argue that property rights in $1995$ cause high GDP in $1995.$ Describe the key assumption to argue that institutions cause economic growth.