I couldn't fit it in the title, but I think the merger of engineering and economics is going to be important going forward. I feel most economists look down on engineering economics (just thinking of variable/fixed operational costs and investment costs, etc), and most engineers think that economists are naive in the characterization of physical domains (like economic policy analyses of energy systems not fully capturing physical principles). I think MIT started a multi-disciplinary program tying those two fields. There is no more relevant field for this than "energy economics". Energy is a physical principles that economists often trivialize... and economics contains ideas that most engineers haven't come across. Yet, most quantitative literature in energy economics shows a stagnating field in terms of new ideas; all papers either do econometrics (statistics applied to economic data), or energy systems models that are surely but slowly merging the two fields. For example, these three papers: 1, 2, 3. 1 does econometrics, and 2 does energy system modeling, while 3 is a recent paper that merges heat transfer principles with microeconomics. I think engineers, with their math skills over many economists, can flood this field with content merging both disciplines.