農業政策與內生成長

Agricultural Policy and Endogenous Growth

本文利用內生成長理論，建構一個開放經濟體系的農業生產模型，探討政府提高所得稅率、提高投入於農村經濟建設比率、提高農地休耕比率、及國外利率的調升，對經濟體系(包括經濟成長率)之影響。在所得稅率提高對經濟成長率的影響方面，取決於政府公共建設對於私部門(農業部門)生產外部效果的大小而定，此結果與Barro (1990)、Futagami et al. (1993)類似；至於總稅收中，使用於公共建設的比率提高，對經濟成長率是否有所助挹，亦取決於政府公共建設對於私部門(農業部門)生產外部效果的大小而定；國外利率的提高，則明顯的不利於國內經濟成長；最後，休耕比率的提高，對經濟成長率的影響，則需視休耕為地力涵養所帶來的效果大小而定。本文亦分析民眾預料到的所得稅率提高之政策對經濟成長率的短期與長期動態效果，發現：若公部門對農業生產的外部效果夠大，則在政策宣告後經濟成長率呈現持續上升走勢；反之，若公部門對農業生產的外部效果較小，提高所得稅率對經濟成長率會有負向的影響，且若要避免經濟成長率過度衰退(短期衝擊過大)，應加大政策宣告與政策執行的時差。至於政府政策對地力的影響方面，所得稅率與休耕比率提高對地力具正向影響；總稅收使用於公共建設支出的比率提高不利於地力；國外利率則不影響地力。

Using endogenous growth theory, we establish an agricultural production model in an small open economy. The aim is to investigate an increasing in the income tax rate, the fraction of public infrastructures in government tax revenues, the foreign interest rate, and the fallow ratio how to influence the economy (including economic growth rate). The growth effect of the income tax rate and the fraction of public infrastructures in government tax revenues are depending on the relative magnitude of public infrastructures production externality. The impact of income tax rate is similar to Barro (1990), and Futagami et al. (1993). An increasing in the foreign interest rate is unfavorable to the domestic economic growth, while a rise in the fallow ratio has an ambiguous impact on the growth rate, which is depending on the effect of fallow ratio on the soil fertility. Moreover, we find that the effect of public infrastructures production externality is larger, economic growth rate will appear an increasing tendency after the policy announcement in the short run. We also find that a rise in the income tax rate and the fallow ratio raises the equilibrium soil fertility, while the effect of the fraction of public infrastructures in government tax revenues is just the opposite. In addition, the foreign interest rate does not influence the soil fertility.