As history shows, the yield gap (the difference between actual and achievable yields) will not necessarily close automatically. Investments in agricultural technologies may be key. Price volatility is fundamental to investment. Price volatility has increased in agriculture in the past decade, leading to higher risks for potential investments. Some of these increased risks may be offset by the certainty offered by credible policies. The US experience indicates that ethanol policy may contribute to yield increases. Analysis suggests that corn use by ethanol plants in the USA may explain a significant part of the observed yield increase. A theoretical framework, centered on downside price‐stabilization effects, is offered here, supported by some US, EU, and Hungarian empirical evidence. The research presented explores whether new ethanol plants resulting from effective biofuel policies could serve as a market mechanism to stimulate investments in farming technologies, triggering increased productivity. A survey of local stakeholders of an ethanol plant in Hungary, the only large‐scale biofuel investment triggered in Europe by the EU's flagship bioenergy policy (the Renewable Energy Directive) suggests that relevant investments may have been stimulated. Over half of the respondent farmers said that the presence of the ethanol plant had stimulated investments in productivity. It is proposed that ethanol or biofuel policies may be effective in closing the yield gap, in effect resulting in additional biomass production and advancing the bioeconomy. With effective cross‐sectoral policies, more biomass for food, feed, bio‐based materials and / or bioenergy purposes can be produced. © 2019 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.