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Country-year data on political violence used by Bagozzi, Hill, Moore and Mukherjee (2015) to introduce the zero-inflated ordered probit in conflict research. The outcome is ordered – no violence, repression, civil war – and its bottom category mixes countries that are structurally at peace with countries that are at risk but happened not to experience violence that year: a zero-inflated ordered outcome. Rows are the complete cases of the published specification.

Usage

data(bp)

Format

A data frame with 1984 rows and 8 variables:

country

Country name.

year

Year.

violence

Ordered factor: none < repression < civil war.

loggdppc

Log real GDP per capita.

parliament

1 if a parliamentary democracy.

disaster

Number of natural disasters in the year.

major_oil

1 if a major oil exporter.

major_primary

1 if a major primary-commodity exporter.

Source

Besley, T. and Persson, T. (2009). Repression or civil war? American Economic Review: Papers and Proceedings, 99, 292-297 (replication data); as analyzed in Bagozzi, B.E., Hill, D.W., Moore, W.H. and Mukherjee, B. (2015). Modeling two types of peace: The zero-inflated ordered probit (ZiOP) model in conflict research. Journal of Conflict Resolution, 59, 728-752.

Provenance and terms

Taken from the public replication archive of the cited article and redistributed here, with the variables renamed and recoded as documented in data-raw/make_data.R, so that the published results can be reproduced; the archive states the original terms of use.

See also

iop(); vignette("iop") and vignette("quantities") analyze these data.

Other datasets: pta, repression

Examples

data(bp)
table(bp$violence)
#> 
#>       none repression  civil war 
#>       1421        387        176 
m <- iop(violence ~ loggdppc + parliament + disaster + major_oil + major_primary |
           loggdppc + parliament + disaster + major_oil + major_primary,
         data = bp, inflate = "bottom")
#> The inflation equation contains no covariate that is excluded from the outcome equation; the split is then identified by functional form alone. An exclusion restriction is advisable.
summary(m)
#> 
#> Inflated ordered probit (inflated category: none)
#> Call:  iop(formula = violence ~ loggdppc + parliament + disaster + major_oil + 
#>     major_primary | loggdppc + parliament + disaster + major_oil + 
#>     major_primary, data = bp, inflate = "bottom")
#> Response levels (in order): none < repression < civil war 
#> N = 1984   inference: analytic 
#> 
#> Outcome equation (ordered probit):
#>                Estimate Std. Error z value Pr(>|z|)    
#> loggdppc       0.001604   0.057695   0.028   0.9778    
#> parliament    -0.095934   0.168983  -0.568   0.5702    
#> disaster       0.273732   0.032817   8.341  < 2e-16 ***
#> major_oil      1.900762   0.450193   4.222 2.42e-05 ***
#> major_primary -0.562976   0.255867  -2.200   0.0278 *  
#> 
#> Cutpoints:
#>                      Estimate Std. Error z value Pr(>|z|)    
#> none|repression        0.5017     0.4151   1.209 0.226854    
#> repression|civil war   1.3985     0.4244   3.296 0.000982 ***
#> 
#> Inflation equation (P(ordered regime); inflated category "none", observed share 0.716, mean fitted P(ordered regime) 0.793):
#>               Estimate Std. Error z value Pr(>|z|)    
#> (Intercept)    20.6179     4.1970   4.913 8.99e-07 ***
#> loggdppc       -2.2461     0.4425  -5.076 3.85e-07 ***
#> parliament     -0.4388     0.4236  -1.036    0.300    
#> disaster       -0.1591     0.1700  -0.936    0.349    
#> major_oil      -4.7601    42.0348  -0.113    0.910    
#> major_primary   3.9884    42.0309   0.095    0.924    
#> ---
#> Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
#> logLik = -1384.26   AIC = 2794.51   BIC = 2867.22   df = 13