本文採用政治經濟學視角討論為什麼財富分配不均導致經濟績效不良。如果初始財富分配很不均或政治投資成本很高或信貸市場很不完善，那麼可以進行政治投資的個體就少，政治市場的競爭就微弱。這樣，在位的政治精英就能制定經濟政策剝削其他階級(中產階級)，這不僅加劇財富分配不均而且導致經濟扭曲嚴重，損害經濟發展。模型表明，(在一定條件下)財富分配格局、社會階層結構和經濟績效長期演進到穩態，該穩態取決於初始財富分配、政治投資成本和信貸市場完善程度。

Why will an unequal wealth distribution lead to poor economic performance? This paper develops a simple model to answer this question from the perspective of political economics. It is shown that, under some condi- tions, the distribution ofwealth, social structure and economic performance emerge as long-run steady equilibrium outcomes depending on the initial wealth distribution, the political investment cost and the credit market’s imperfection. The more unequal the initial wealth distribution or the higher the political investment cost or the greater the degree of imperfection in the credit market, the less the individuals are able to invest in political capital. Therefore, the political market is less competitive and the incumbent political elite can levy a high tax on the middle class. This not only worsens wealth inequality but also undermines economic development.