Causation
When a change in one variable precipitates a change in another variable
Correlation
An apparent connection between variables
Empirical statement
An assertion of a fact that can be proven
Normative statement
A value judgement, usually in the form of should or ought to
Quantitative data
Observations made using statistical techniques
Qualitative data
Text-based descriptions
Human Development Index (HDI)
An aggregate measure of life expectancy, education, and per capita income
Gross domestic product (GDP)
The total value of goods and services produced in a country in a year
GDP per capita
Gross domestic product divided by population
GDP growth rate
The percentage of GDP growth over a period of time
Gini index (coefficient)
A measure of income inequality within a country
Freedom House
A nongovernmental organization that advocates for democracy and human rights, measuring freedom around the world
Democratic consolidation
The process by which a regime has developed stable democratic institutions and significant protections of civil liberties, leaving it unlikely to return to authoritarianism
Corruption
The abuse of official power for personal gain
Corruption Perceptions Index
A measure of how corrupt a system is believed to be
Strong state
A state that is capable of providing necessary government services to its citizens
Failed state
A state that has lost control over all or part of its territory
Fragile State Index
A measure of state strength, highlighting concerns about fragile and failed states