R D在借貸限制下對貧富不均的影響

Abstract

美國跨州資料呈現出R D與貧富不均有著正相關性，本文建立異質性個人模型，探討給定不同的企業家能力、勞動能力、以及秉賦資產之下，個體在借貸限制之下如何進行職業選擇以及企業家如何進行R D的決策，同時探討此決策如何影響各州的貧富不均。模型結果在捕捉財富分配以及所得分配上有著高度的配適性，在財富分配上尤其貼近由美國IRS資料計算出的財富分配。此外，模型結果預期寬鬆的借貸限制將會鼓勵企業融資進行研發，同時透過研發享有較高的利潤進而加重貧富不均的分配，然而整體社會的總產出則因研發而增加。

In this paper, I show that the income inequality measured by either the GINI coefficient or the top income share in the United States has a positive correlation with R D. Besides, the R\ D level in each state positively correlates to the inequality in each state. I construct the heterogeneous agent model to incorpo­rate the idea of R D and borrowing constraints to explain how financial constraints worsens inequality through R D. The agent equipped with different entrepreneurial ability, working ability, and wealth level makes occupational choice and entrepreneur decides optimal research level to maximize income. The model prediction matches the observed distributional inequality calculated from IRS data quite well and in­dicates that the research opportunity makes rich people richer and worsens income inequality while the total output is higher in the meantime.