cw_democracy            Democracy (Correlates of War System)
cw_gdppop               GDP, Population, and GDP per Capita (Correlates
                        of War System)
cw_gw_panel             State-Year Panel for Merging G-W Data
                        (Correlates of War)
cw_system               States (Correlates of War System)
gw_cw_panel             State-Year Panel for Merging Correlates of War
                        Data (Gleditsch-Ward)
gw_democracy            Democracy (Gleditsch-Ward System)
gw_gdppop               GDP, Population, and GDP per Capita
                        (Gleditsch-Ward System)
gw_system               States (Gleditsch-Ward System)
state_panel             Create a Panel of State-Years from the
                        Correlates of War or Gleditsch-Ward system.
