cull lumber

The standard highways and substandard roads have statistically significant and positive effects on growth and poverty reduction,and the former has much more impact than the latter.

结果表明:四川道路基础设施和经济增长之间存在着双向因果关系;具有不同质量的等级公路和等外路对经济增长和减缓贫困均具有统计上的显著影响,而且等级公路比等外路的作用更为显著。