# Incorporating New Technologies in EEIO Models
## 5 Conclusions and Discussion  
Here, a generalized methodology was proposed to analyze the economic and environmental impacts of new technologies. This methodology is innovative and flexible since (1) it can be applied to any new product for which the perfect substitution assumption is reasonable, (2) for any number of industries producing the new product and (3) for rectangular Input-Output matrices and (4) it can be computationally implemented in any existing EEIO model. This is not the first attempt to analyze the introduction of new technologies or products using IO models. The previous attempts were based on specific technologies. This is the first time a generalized methodology has been proposed to incorporate any new commodity to EEIO models, specifically for rectangular matrices. This is the case for the US Make and Use tables, which follow the Commodity-by-Industry approach [7]. This methodology includes how to augment the Make and Use tables and how to rebalance them via an analytical approach. Its use is exemplified using the case of woody-based biofuels produced with a mix of three technologies that partially replace petroleum-based fuels. The methodology is presented considering the Make and Use tables structure for the United States, published by the Bureau of Economic Analysis (BEA). This methodology is powerful as it allows analysis of the environmental impacts of new products and the technologies that produce them, considering all the short-term ripple effects in the economy. This is something that cannot be done with process-based LCA due to system boundary limitations. It allows answering questions such as,  
* What if 50% of the plastics currently used are replaced with bio-plastics? \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Units** & **All Technologies** & **Gas Fermentation** & **Guerbet Reaction** & **Fischer Tropsch** \\ \hline Greenhouse Gases & kg CO\({}_{2}\) eq & 0.215 & 0.229 & 0.21 & 0.207 \\ \hline Eutrophication & & & & & \\ Potential & g N eq & 0.622 & 1.21 & 0.251 & 0.416 \\ \hline Acidification & & & & & \\ Potential & g SO\({}_{2}\) eq & 3.57 & 5.29 & 2.13 & 3.29 \\ \hline Human Health— & & & & & \\ Respiratory & g PM2.5 eq & 0.375 & 0.487 & 0.298 & 0.342 \\ Effects & & & & & \\ \hline Energy Use & MJ & 80.22 & 90.49 & 69.14 & 81.02 \\ \hline Nonrenewable & & & & & \\ Energy Use & MJ & 2.86 & 3.04 & 2.80 & 2.74 \\ \hline Renewable Energy & & & & & \\ Use & MJ & 77.37 & 87.45 & 66.34 & 78.28 \\ \hline Land use & m2*yr & 13.06 & 13.85 & 11.59 & 13.73 \\ \hline Jobs Supported & \(10\times 10^{-6}\) jobs & 10.24 & 13.05 & 9.82 & 7.91 \\ \hline Freshwater & & & & & \\ withdrawals & kg & 17.70 & 21.25 & 13.13 & 18.69 \\ \hline Value Added & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Biofuels impacts per GGE with a 3.68% substitution. * Which technology generates less environmental impact, including the ripple effects of all inputs? * Which economic sectors will increase or decrease their emissions due to the addition of new industries? * What environmental impacts of producing a new product are due to the production of the supply chain inputs? The methodology has limitations. First, it is only suitable for assessing short-term equilibrium impacts [11; 12; 18]. IO models only allow the evaluation of how the introduction of this new commodity will generate a ripple effect of purchases through its providers of inputs, the providers of the providers and so on; however, they cannot represent how the economic structure will change in the long term. For example, it does not include the introduction of new additional products or sectors that may appear as a result of the new product being introduced. Nor does it include the disappearance of existing industries or commodities. It also does not include existing industries changing their production recipes due to the introduction of the new technologies and product. A Computable General Equilibrium model (CGE) or other macro-economic model may be suitable to model these dynamic responses.