近年來中國一直致力于擴大內需,但內需仍然不足,其原因何在?本文通過擴展戴蒙德世代交疊模型構建了總體內需模型,考察了人口結構變化對內需的影響,并利用1991年—2011年中國省級面板數據進行了實證檢驗。系統廣義矩估計和門檻回歸結果表明:少兒撫養比對我國內需具有顯著的正向影響,且其正向影響隨著經濟發達程度的增加而略微減弱;而老年撫養比對我國內需具有顯著的負向影響,且其負向影響隨著經濟發達程度的增加而增強。并發現:適度的人口增長有助于擴大內需,人口城鎮化水平與內需呈現正相關關系,而城鄉人均收入差距與內需呈現"倒U型"關系,人均收入的提高和地區經濟增長對擴大內需均具有積極影響。最終結論表明:我國少兒撫養比的不斷下降和老年撫養比的持續上升對內需產生了雙重抑制,"少子化"和"老齡化"并存的人口結構新特征是我國內需不足的重要原因之一,全面放開"二孩政策"有助于實現擴大內需的戰略目標。

There has been a question that why China′s domestic demand is still insufficient,though it has been devoted to expanding domestic demand for years? Based on extended Diamond overlapping-generation model,this paper builds overall domestic demand model to investigate the influence of demographic changes on domestic demand and does the empirical test with provincial panel data of China from 1991 to 2011. Estimated results of system GMM and threshold regression reveal that child dependency ratio has a significant positive impact on China′s domestic demand,and this impact slightly weakens with higher levels of economic development.On the other hand,elderly dependency ratio has a significant negative impact on China′s domestic demand,and this negative impact strengthens with higher levels of economic development.Besides,this paper finds that moderate population growth is beneficial to expand domestic demand. Population urbanization positively correlates with domestic demand. Urban-rural income gap has an inverted U-shape relationship with domestic demand. Both level of per capita income and regional economic growth have a positive effect on increasing domestic demand. Final conclusion shows that both the declining child dependency ratio and increasing elderly dependency ratio are detrimental to domestic demand,and the coexistence of ″declining birthrate″and ″aging″,which is the new feature of demographic structure,is one of the most important causes for insufficient domestic demand. The opening up of two-child policy will contribute to expanding domestic demand.