Two recent OECD Taxation Working Papers (WP24 and WP27) caution that improperly designed fiscal incentives for research and development and innovation can have unintended and undesirable consequences. While potentially having positive effects, some tax policies can favor incumbent firms, encourage small firms to undertake less efficient activities, and create arbitrage and rent-seeking activity. Increased R&D activity in one country may not result in an overall increase in global innovation if it is simply shifted from another country. More research is needed on fiscal incentives' actual effects on both the quantity and quality of overall global R&D and its potential spillovers to other sectors of the global economy before piling on more tax and fiscal incentives for R&D. Negative effective tax rates from multiple fiscal incentives and tax arbitrage may be more detrimental than beneficial to overall R&D and innovation.