No Green Growth Without Innovation

This Policy Brief, co-written by Senior Non-Resident Fellow Philippe Aghion, Senior Resident Fellow Reinhilde Veugelers and David Hemous of Harvard University, attempts to change the terms of the debate surrounding climate change policy. The authors argue that policymakers should do more to encourage innovation and investment in Â?greenÂ? research and development rather than focusing solely on the setting of a carbon price. Using a model developed by Aghion in a previous paper, they argue that a carbon price would have to be about 15 times higher in the first five years and 12 times higher in the next five years if innovation is not properly subsidized by governments. The authors also provide several policy recommendations for incentivising this type of Â?green growthÂ? in the private sector.

No green growth without innovation. Bruegel Policy Brief 2009/07, November 2009

The 'green growth' debate is taking place in an oversimplified setting, largely disregarding the innovation factor. Technologies to mitigate climate change are being treated as given, or as emerging spontaneously, ignoring the fact that the portfolio of technologies available tomorrow depends on what is done today. This can easily lead to a misguided preference, either for subsidising the use of relatively inefficient technologies or for postponing action to later in the hope that new technologies will become available which will reduce the cost of fighting climate change. But the radical new emissions-free 'backstop technologies' we will need are not yet available, or else still far from the market. To foster their emergence the 'green innovation machine' must be turned on

The Environment and Directed Technical Change

This paper introduces endogenous and directed technical change in a growth model with environmental constraints. A unique final good is produced by combining inputs from two sectors. One of these sectors uses "dirty" machines and thus creates environmental degradation. Research can be directed to improving the technology of machines in either sector. We characterize dynamic tax policies that achieve sustainable growth or maximize intertemporal welfare. We show that: (i) in the case where the inputs are sufficiently substitutable, sustainable long-run growth can be achieved with temporary taxation of dirty innovation and production; (ii) optimal policy involves both “carbon taxes” and research subsidies, so that excessive use of carbon taxes is avoided; (iii) delay in intervention is costly: the sooner and the stronger is the policy response, the shorter is the slow growth transition phase; (iv) the use of an exhaustible resource in dirty input production helps the switch to clean innovation under laissez-faire when the two inputs are substitutes. Under reasonable parameter values and with sufficient substitutability between inputs, it is optimal to redirect technical change towards clean technologies immediately and optimal environmental regulation need not reduce long-run growth.Environment, Exhaustible Resources, Directed Technological Change, Innovation

The Environment and Directed Technical Change

This paper introduces endogenous and directed technical change in a growth model with environmental constraints. A unique final good is produced by combining inputs from two sectors. One of these sectors uses “dirty” machines and thus creates environmental degradation. Research can be directed to improving the technology of machines in either sector. We characterize dynamic tax policies that achieve sustainable growth or maximize intertemporal welfare. We show that: (i) in the case where the inputs are sufficiently substitutable, sustainable long-run growth can be achieved with temporary taxation of dirty innovation and production; (ii) optimal policy involves both “carbon taxes” and research subsidies, so that excessive use of carbon taxes is avoided; (iii) delay in intervention is costly: the sooner and the stronger is the policy response, the shorter is the slow growth transition phase; (iv) the use of an exhaustible resource in dirty input production helps the switch to clean innovation under laissez-faire when the two inputs are substitutes. Under reasonable parameter values and with sufficient substitutability between inputs, it is optimal to redirect technical change towards clean technologies immediately and optimal environmental regulation need not reduce long-run growth.environment; exhaustible resources; directed technological change; innovation

Carbon taxes, path dependency and directed technical change: evidence from the auto industry

Can directed technical change be used to combat climate change? We construct new firm-level panel data on auto industry innovation distinguishing between “dirty” (internal combustion engine) and “clean” (e.g. electric and hybrid) patents across 80 countries over several decades. We show that firms tend to innovate relatively more in clean technologies when they face higher tax-inclusive fuel prices. Furthermore, there is path dependence in the type of innovation both from aggregate spillovers and from the firm's own innovation history. Using our model we simulate the increases in carbon taxes needed to allow clean to overtake dirty technologies

Credit Constraints, Cyclical Fiscal Policy and Industry Growth

What are the effects of cyclical fiscal policy on industry growth? We show that industries with a relatively heavier reliance on external finance or lower asset tangibility tend to grow faster (in terms of both value added and of labor productivity growth) in countries that implement fiscal policies that are more countercyclical. We reach this conclusion using Rajan and Zingales׳s (1998) difference-in-difference methodology on a panel data sample of manufacturing industries across 15 OECD countries over the period 1980–2005.Economic

Credit Constraints, Cyclical Fiscal Policy and Industry Growth

This paper evaluates whether the cyclical pattern of fiscal policy can affect growth. We first build a simple endogenous growth model where entrepreneurs can invest either in short-run projects or in long-term growth enhancing projects. Long-term projects involve a liquidity risk which credit constrained firms try to overcome by borrowing on the basis of their short-run profits. By increasing firms' market size in recessions, a countercyclical fiscal policy will boost investment in productivity-enhancing long-term projects, and the more so in sectors that rely more on external financing or which display lower asset tangibility. Second, the paper tests this prediction using Rajan and Zingales (1998)'s diff-and-diff methodology on a panel data sample of manufacturing industries across 17 OECD countries over the period 1980-2005. The evidence confirms that the positive effects of a more countercyclical fiscal policy on value added growth, productivity growth, and R&D expenditure, are indeed larger in industries with heavier reliance on external finance or lower asset tangibility.

Automating labor: evidence from firm-level patent data

Do higher wages lead to more automation innovation? To answer this question, we first introduce a new measure of automation by using the frequency of certain keywords in patent text to identify automation innovations in machinery. We validate our measure by showing that it is correlated with a reduction in routine tasks in a cross-sectoral analysis in the US. Then we build a firm-level panel dataset on automation patents. We combine macroeconomic data from 41 countries and information on geographical patent history to build firm-specific measures of lowskill and high-skill wages. We find that an increase in low-skill wages leads to more automation innovation with an elasticity between 2 and 4. An increase in highskill wages tends to reduce automation innovation. Placebo regressions show that the effect is specific to automation innovations. Finally, we use the Hartz labor market reforms in Germany for an event study and find that they are associated with a relative reduction in automation innovations

The Environment and Directed Technical Change

This paper introduces endogenous and directed technical change in a growth model with environmental constraints and limited resources. A unique final good is produced by combining inputs from two sectors. One of these sectors uses "dirty" machines and thus creates environmental degradation. Research can be directed to improving the technology of machines in either sector. We characterize dynamic tax policies that achieve sustainable growth or maximize intertemporal welfare, as a function of the degree of substitutability between clean and dirty inputs, environmental and resource stocks, and cross-country technological spillovers. We show that: (i) in the case where the inputs are sufficiently substitutable, sustainable long-run growth can be achieved with temporary taxation of dirty innovation and production; (ii) optimal policy involves both "carbon taxes" and research subsidies, so that excessive use of carbon taxes is avoided; (iii) delay in intervention is costly: the sooner and the stronger is the policy response, the shorter is the slow growth transition phase; (iv) the use of an exhaustible resource in dirty input production helps the switch to clean innovation under laissez-faire when the two inputs are substitutes. Under reasonable parameter values (corresponding to those used in existing models with exogenous technology) and with sufficient substitutability between inputs, it is optimal to redirect technical change towards clean technologies immediately and optimal environmental regulation need not reduce long-run growth. We also show that in a two-country extension, even though optimal environmental policy involves global policy coordination, when the two inputs are sufficiently substitutable environmental regulation only in the North may be sufficient to avoid a global disaster.