Dr. Kevin Hanrahan:

I thank the Deputy for his really insightful and sharp questions. To pull on the ball from Dr. Daly with regard to the unified model, the models are representations of reality but all models are wrong, although some are useful. The demand from users of our analysis is that the models capture the complexities of the issues at hand. Our stakeholders want to know what happens to the numbers of cows and sheep, how much oats are grown and so on. When the models are asked to capture that level of complexity, unifying them is an almost impossible task. An energy system model might run on a time step of hours or minutes. It is really a massive task and I am not sure unifying them would yield benefits commensurate with the amount of work that would be needed to do so. That is my own perspective.

On the gaps, the work of the committee and the feedback from fellow members has pointed to a gap that we are going to work to fill. We have to think of how to do so. I am referring to the idea that some of the changes we considered would lead to losses of output from agriculture. Some of the land resources in question could be used to produce other things but those other things often involve doing things that have never been done before or never been done before at scale. How can that be represented in a model? That is something we need to tackle. To give an example, the quantity of Irish agricultural land used to grow horticultural products is minute. It has not been very large since before the Famine. How do we develop parameters for a model of a reality that has not existed in modern history? That is a big challenge. We need to think about how to fill that gap.

The bigger gap - and this speaks to the concern about the ability of the models we have used in this work to consider wider societal issues - is really the absence of a unified macroeconomic models analysis that could tell us something more about the distributional implications across high-skilled and low-skilled employment, rural and urban areas and different strata. This would also involve different ways of thinking about society and different industries. I know the ESRI did work for the committee but its involvement in the process came so late in the day that its work was not able to form a fundamental pillar of the technical report. Given the scale of the societal change we are considering, it behoves Ireland's socioeconomic and analytic community to be much more involved in this question because it involves changing the bedrock of an awful lot of things we need to think about.

There in one other point of difference. When thinking about agriculture specifically, because we are so export-oriented, in constructing models we need to think about what is happening in the rest of the world in terms of agricultural markets, agricultural policy and, down the road, climate change policy with regard to how it affects other industries in competing countries and demand for the type of products we produce in Ireland. That is a very important consideration and one of the reasons it is so difficult to move to a 50-year time horizon because that involves making enormous assumptions about what agricultural policy will look like between now and then. That will predetermine the path you travel on to a great extent. I am not an expert in forecasting how policy will develop but the role of policymakers domestically and at the European and global levels is endogenous. It affects all of this stuff and we need to think about how we reflect that in our work.