Based on a new panel data,we find a very significant and robust empirical relation:there is distinct crowding out effect of government debt to private investment.After controlling a few variables emphasized by investment literature,the higher government debt-GDP ratio is,the lower private investment rate is.This kind of negative effect of government debt may come from the fluctuation of government debt-GDP ratio.There are enough attritions in the real world that lapse the Ricardian equivalence proposition.
Based on a new panel data, we find a very significant and robust empirical relation:government debt is harmful to longrun economic growth.After controlling a few veriables emphasized by economic growth literature, the higher government debtGDP ratio is, the lower longrun economic growth rate is.This kind of negative effect of government debt is more obvious in developing countries,and may come from the fluctuation of government debtGDP ratio.We also find a few familiar results on economic growth empirical research:there is conditional convergence to some extent, total investmentGDP ratio and life expectancy is positive to economic growth,etc.
李嘉图等价性命题是研究最优政府债务问题的出发点，如果人们出于跨代利他动机留下遗产（Barro，1974）或赡养长辈（Carmichael，1982），李嘉图等价性命题成立，以税收方式还是发行债券的方式为政府支出筹资就没有任何实质性影响，不存在最优政府债务问题。然而，人们跨代转移财富并不一定出于利他动机，也可能是家族成员间的相互保险（Abel，1985）；或者代间策略行为（Kotlikoff et al.，1990）；或者只不过由于人们寿命的不确定（Blanchard，1985）。在这些情形下，李嘉等价性都不会成立。
