According to the lesson, why did Germany's economy nosedive following World War I?

At first Germany tried to recover from the war by way of social spending. Germany began creating transportation projects, modernization of power plants and gas works. These were all used to battle the increasing unemployment rate. Social spending was rising at an unbelievable rate. In 1913 the government was spending approximately 20.5 per resident; by 1925 it had risen to almost 65 marks per resident and finally in 1929 it reached over one hundred marks per resident. The elevating amounts of money which were used for social spending combined with plummeting revenues caused continuing deficits. Eventually the municipal finance collapsed in 1930. Although it seemed as if the collapse was due to debt, in actuality ordinary budgets were the reason for the initial collapse