We translate Hotelling's continuous-time, exhaustible resource extraction Model of 1931 into a linear program of present value extraction cost minimization subject to a stock endowment and period by period demand constraints. The appropriate form of the demand constraints allows for resource...

Tackling climate change is one of the highest challenges which the world economy is currently facing. The European Green Deal, adopted in 2019, sets the European roadmap towards a net-zero greenhouse gas emissions economy. The food system is heavily responsible for greenhouse gas emissions and...

We study general dynamic programming problems with continuous and discrete choices and general constraints. The value functions may have kinks arising (1) at indifference points between discrete choices and (2) at constraint boundaries. Nevertheless, we establish a general envelope theorem:...

We develop a tractable RBC model of the stock market with heterogenous firms. Shares value rests on the rent extracted from proprietary technology à la Dixit-Stiglitz. We prove the existence and uniqueness of the fundamental equilibrium. Closed form solutions are provided for the market...

Since the 1970s, there have been significant changes in firm dynamics within and across industries in the US. Industries are increasingly dominated by a small number of large firms ("superstars"). Markups, market concentration, profits, and R&D spending are increasing, whereas business dynamism,...

This paper develops a theory of oligopoly and markups in general equilibrium. Firms compete in a network of product market rivalries that emerges endogenously out of the characteristics of the products and services they supply. My model embeds a novel, highly tractable and scalable demand system...