This paper attempts to analyse the effectiveness of government fiscal policies through the bond financing when an economy's growth rate is slowing down. Firstly, by introducing the rate of unemployment, defined as a risk probability that consumers and firms bear in their decision making into a macroeconomic model under a government budget restraint, the performances of transitory equilibra are analysed, and it is found that the higher is the rate of unemployment, the smaller are the impact multipliers of governament expenditure. Secondly, making a dynamic analysis with this model, it is shown that the smaller is the government deficit, near a transitory equilibrium, the higher is the likelihood that the conditions for dynamic stability of an economy will be satisfied. Finally, it is shown that an increase in government expenditures through bond financing will result in a larger government deficit and a rise in interest rates, in an economy which has already suffered from a large deficit. A purpose of this study is to give a theoretical basis to a macroeconomic analysis of the Postwar Japan, published in Hamada (1984). This is an extension of Hamada and Shiozawa (1894).