Mohamad Adhami

Job Market Paper 

Quantifying Knowledge Spillovers Using Firm and Product Dynamics

Awarded Best Job Market Paper by the European Economic Association and Unicredit Foundation

Intertemporal knowledge spillovers are a common rationale for government support of innovation, yet estimates of their magnitude remain scant. Since many innovations are not patented, I use data on product and firm dynamics, interpreted through the lens of a new growth model, to quantify these spillovers. In the model, stronger spillovers accelerate improvements across successive generations of new products and thereby increase the rate at which incumbent products lose market share and exit. At the same time, idiosyncratic product volatility generates turnover even absent spillovers. Exit by age then allows separate identification of these competing drivers of turnover. Using data on all U.S. nonfarm private employer businesses, I estimate that spillovers drive an 11 to 28 percentage point wedge between social and private returns to innovation under laissez-faire.

Working Papers 

Variable Markups, Incomplete Pass-Throughs, and R&D Misallocation

(with Jean-Félix Brouillette and Emma Rockall) 

Motivated by growing evidence on variable markups and positive yet incomplete cost pass-through, we develop a growth model featuring monopolistically competitive firms facing non-isoelastic demand and making forward looking investments in R&D to improve their process efficiency. By featuring a lower elasticity of demand at lower prices, the model endogenously generates higher markups for more productive firms and incomplete pass-through of cost savings. A novel implication is that such variable markups lead to R&D misallocation: by acting as a size-dependent wedge, higher markups disproportionately shrink the scale and depress the private R&D returns of the most productive firms. We quantify the model using French firm-level data and find this R&D misallocation slows aggregate growth by 0.9 percentage points. This effect is driven entirely by markup dispersion, not the average level of markups.

Population and Welfare: Measuring Growth when Life is Worth Living

(with Mark Bils, Chad Jones, and Pete Klenow) Conditionally Accepted, AEJ: Macroeconomics

Economic growth is typically measured in per capita terms. A long tradition in philosophy, however, suggests that social welfare may depend on the number of people as well. To illustrate how much this matters quantitatively, we decompose welfare growth—measured in consumption-equivalent (CE) units—into contributions from rising population and rising per capita consumption. Because of diminishing marginal utility from consumption, population growth is scaled up by a value-of-life factor that empirically averages nearly 3 across countries since 1960. Population increases are therefore a major contributor to growth if one takes a total utilitarian perspective.

Work in Progress

Carbon Neutral Growth: Evidence from French Manufacturing

(with Thibault Ingrand)

This paper studies decarbonization in the French manufacturing sector, where energy-related emissions have fallen sharply despite continued output growth. Using establishment-level data on energy consumption, we decompose this trend. We find declining carbon intensity of energy (emissions/energy) and falling energy intensity (energy/output) account for 40% and 60% of the trend, respectively. The reduction in carbon intensity is primarily due to electrification. We find this electrification is driven almost entirely by within-establishment changes, with little role for reallocation across producers. In contrast, for the decline in energy intensity, both reallocation and within-firm improvements are important: reallocation of activity across industries accounts for 20% of the gains; within industries, the vast majority of the decline (85% of the within-industry effect) stems from incumbent firms improving their own efficiency.

Teaching Experience

TA for Pete Klenow, Econ 211 (first year PhD Macro) 
Recognized by the department with an Outstanding Teaching Assistant Award.
Teaching Evaluations: Winter 2023, Winter 2024, Winter 2025