Kvasnicka and Bethmann (2007) believe that posterity's perfect understanding of the similar and combined effects of these wars can be enhanced by making a holistic view on the effects these wars had on migration, global population sex ratio and labor availability, and world order. Each of these perspectives would now be looked in context to see how the effects of the two wars were similar on them.
In his book An Illustrated History of the First World War, Keegan (2001) maintains that the world's population knew an unprecedented trend in location and relocation during WWI. This location and relocation was usually from one country to another or from one city/town to another. Such movement was usually to flee from danger from one part of the world to another part of the world where danger was not so imminent. According to Keegan, such movement was ever feasible because, although this war was termed a world war, it practically did not involve all the countries of the world per se. Infact, some authors like Keegan himself, Banks (2002); Gilbert (2004) have persistently held that the first world war was a European war, arguing that the US role in the war was more of an arbitration or mediating one. So some countries remained neutral and were favorable destinations for people to move from war-torn countries like Germany, Britain, France and Belgium.
Meanwhile, contributions from authors on the Second World War pointing to the same issue of migration abound. Karsmakers (2003); Kvasnicka and Bethmann (2007) and Cantor and Land (1985) revealed that the bombings of the second world war made people to leave their homes to seek refuge elsewhere more that in a y recorded period in history. Such movement to flee from danger and seek refuge is consonant to the same scenario that was lived in the First World War. In view of the above, it can be seen that the international system knew a trend of migration for the periods 1914 to 1918 and 1939 to 1945 as people left their homes as refugees to flee bombings and other atrocities caused by the war.
Global Population Sex Ratio and labor availability
One of the most disastrous economic, social and demographic effects that were common to these wars was the decimation of the male population. As Kvasnicka and Bethmann (2007) put it, men were to provide the force and backup for war in each country, while the women stayed home to carry out duties like child upbringing. They argued that as each country lost soldiers in war fronts, the male to female ratio drastically reduced. One of the most severe impacts of this reduction in male to female ration was the fact that jobs hitherto undertaken by men were now occupied by women. Infact, in one study by Vari (1992), it was revealed that over 600,000 thousand Italians were killed in the First World War such that jobs like driving and other major production jobs in industries were occupied by women.