Re: China's defence budget for 2013: RMB 740 billion, $118 billion, up 10.7% over 20
First you have to take into account that the numbers below exludes the off balance sheet spending for the military of both countries. But for the sake of argument we will just take the official figures for what it is.
First lets compare the sizes of the US military and the PLA. The US military as it now stands is about 1,43 million man strong which includes the US coast guard and the PLA based on the recently released white paper is 1,48 million man strong and if you add the second artillery corps that are not included in the numbers then you get a number of about 1,58 million man strong. The base budget of the US military is 554,2 billion $ for 2013 (that excludes the Afghan war costs) and for the PLA its 115,7 billion $ for 2013. The reserve forces are about 800000 men each.
So on average the US spends about 387553 $ for every active soldier in the military and China spends 73228 $ per active soldier and that means that the US is spending 5,3x more per active soldier then China.
But here comes the tricky part the per capita in come of the US is about 8,2x higher than in China and China doesn't have overseas operations except for anti piracy missions in the Indian Ocean. While the US has about a 1000 military bases all over the world and spread over more than 100 nations. Maintaining that infrastructure cost quite a bit of money. And the wages for the average Chinese officer and soldier is many times lower than that of the US military. And now that the PLA is getting most of her weapons from domestic sources means that procurement costs for the PLA are also much lower.
But other costs for both the PLA and the US military remains the same like their imports of weapons and raw material that they use to make those weapons. The cost difference comes down to labour.
US military spending over the past few years have fallen to 4,1% of GDP and that of China's to 1,4% of GDP.