How would you explain this methodology and could you identify the independent, dependent, control variables, how would you defen
d the validity and reliability of the variables, and what is the testable hypothesized relationship between the independent and dependent variable? Data and Dependent Variable
We collected data for 145 countries over the time period 1970-2000.16 The data are structured in terms of country-year observations and, after dropping 72 such cases for which we do not have any information on the migration data (discussed below), our sample comprises 3,919 country-years.17 For the dependent variable, we rely on the information in the Global Terrorism Database (GTD) that defines terrorism as “the premeditated use or threat to use violence by individuals or subnational groups against noncombatants in order to obtain a political or social objective through the intimidation of a large audience beyond that of the immediate victims” (Enders, Sandler and Gaibulloev, 2011, p.321). This data set provides a count variable on the number of terrorist attacks – both national and transnational – that occurred within a country’s geographic boundaries.18 We use a modified version of the count variable of terrorist attacks: due to the skewed distribution of the number of terrorist attacks in a country, which is primarily driven by the large number of zeros in the data, and since our estimators require a (quasi-) continuous dependent variable, we take the natural logarithm of the count after adding the value of 1 (to avoid calculating the log of 0.
