We study the potential for rational bubbles in the innovation sector to affect long term economic growth. We show that stock market prices of research and development (R&D) firms can include a bubble component when credit constraints are present. Bubbles are self-sustained in equilibrium by a “liquidity” premium that originates when credit constraints are relaxed. Bubbles expand the borrowing and production capacities of R&D firms, stimulate innovation, and increase the growth rate. Small firms benefit more from bubbles than big firms. Bubbles are magnified by tighter credit constraints and scarce investment opportunities. Thus, financially underdeveloped countries benefit more from bubbles. Finally, we show that bubbles can create permanent reallocation effects that benefit the innovation sector over other sectors.

我们研究了创新领域理性泡沫影响长期经济增长的潜力。我们表明，在存在信用约束的情况下，研发公司的股票市场价格可以包括泡沫成分。泡沫是通过放宽信贷约束而产生的“流动性”溢价在均衡中自我维持的。泡沫扩大了研发公司的借贷和生产能力，刺激了创新并提高了增长率。小企业比大企业受益于泡沫。信贷紧缩和投资机会稀缺加剧了泡沫。因此，金融不发达国家从泡沫中受益更多。最后，我们证明泡沫可以产生永久性的重新分配效应，从而使创新部门比其他部门受益。