Michael Webb

Economics Ph.D. student at Stanford

I am a fourth-year Ph.D. student in Economics at Stanford. I work on artificial intelligence, the labor market, and economic growth.

I previously studied at Balliol College, Oxford and MIT, and have been a classicist, an organist and choral conductor, a writer for The Economist, part of a lab at the Harvard School of Public Health, and (very briefly) a war correspondent.

If you have questions about my research, I'd love to hear from you! My email is mww@stanford.edu.

Working papers

Are Ideas Getting Harder to Find?

Nick Bloom, Chad Jones, John Van Reenen, Michael Webb

In many growth models, economic growth arises from people creating ideas, and the long-run growth rate is the product of two terms: the effective number of researchers and their research productivity. We present a wide range of evidence from various industries, products, and firms showing that research effort is rising substantially while research productivity is declining sharply. A good example is Moore's Law. The number of researchers required today to achieve the famous doubling every two years of the density of computer chips is more than 18 times larger than the number required in the early 1970s. Across a broad range of case studies at various levels of (dis)aggregation, we find that ideas — and in particular the exponential growth they imply — are getting harder and harder to find. Exponential growth results from the large increases in research effort that offset its declining productivity.


A Cross-Country Comparison of Dynamics in the Large Firm Wage Premium

Emanuele Colonnelli, Joacim Tåg, Michael Webb, Stefanie Wolter

Forthcoming in AEA Papers and Proceedings, May 2018

We provide stylized facts on the existence and dynamics over time of the large firm wage premium for four countries. We examine matched employer-employee micro-data from Brazil, Germany, Sweden, and the UK, and find that the large firm premium exists in all these countries. However, we uncover substantial differences among them in the evolution of the wage premium over the past several decades. Moreover, we find no clear evidence of common cross-country industry trends. We conclude by discussing potential explanations for this heterogeneity, and proposing some questions for future work in the area.

Effectiveness of Dietary Policies to Reduce Noncommunicable Diseases

Ashkan Afshin, Renata Micha, Michael Webb, Simon Capewell, Laurie Whitsel, Adolfo Rubinstein, Dorairaj Prabhakaran, Marc Suhrcke, and Dariush Mozaffarian

In Disease Control Priorities (third edition): Volume 5, Cardiovascular, Respiratory, and Related Disorders, edited by D. Prabhakaran, S. Anand, T. A. Gaziano, J.-C. Mbanya, Y. Wu, and R. Nugent. Washington, DC: World Bank. November 2017.

This chapter reports that in nearly every region, suboptimal diet remains the leading risk factor for poor health; hunger and malnutrition result in substantial burdens and contribute to the incidence and prevalence of noncommunicable diseases (NCDs). Specific population interventions, including taxation and subsidies, food regulations, mass media campaigns, and school and workplace interventions, appear effective in improving diet, and many such interventions may prove highly cost-effective (efficient health gained per dollar spent) or even cost saving (health gains with reduced overall spending). These interventions prove highly attractive and complement the preventive health system strategies promoted in high-, middle-, and low-income countries. Selected policy interventions may also reduce health disparities. Specific knowledge gaps remain in quantitative effectiveness and cost-effectiveness of several dietary policies in different settings and within different population subgroups, however. These gaps highlight the urgent need for governments, foundations, advocacy groups, and private industry to prioritize relevant implementation and evaluation of these approaches.

Cost Effectiveness of a Government Supported Policy Strategy to Decrease Sodium Intake: Global Analysis Across 183 Nations

Michael Webb, Saman Fahimi, Gitanjali M Singh, Shahab Khatibzadeh, Renata Micha, John Powles, Dariush Mozaffarian

BMJ, January 2017, 356: p. i6699

We quantified the cost effectiveness of a government policy combining targeted industry agreements and public education to reduce sodium intake in 183 countries worldwide. We studied a “soft regulation” national policy that combines targeted industry agreements, government monitoring, and public education to reduce population sodium intake, modeled on the recent successful UK program. To account for heterogeneity in efficacy across countries, a range of scenarios were evaluated, including 10%, 30%, 0.5 g/day, and 1.5 g/day sodium reductions achieved over 10 years. We characterized global sodium intakes, blood pressure levels, effects of sodium on blood pressure and of blood pressure on cardiovascular disease, and cardiovascular disease rates in 2010, each by age and sex, in 183 countries. Country specific costs of a sodium reduction policy were estimated using the World Health Organization Noncommunicable Disease Costing Tool. Country specific impacts on mortality and disability adjusted life years (DALYs) were modeled using comparative risk assessment. We only evaluated program costs, without incorporating potential healthcare savings from prevented events, to provide conservative estimates of cost effectiveness. Worldwide, a 10% reduction in sodium consumption over 10 years within each country was projected to avert approximately 5.8 million DALYs/year related to cardiovascular diseases, at a population weighted mean cost of I$1.13 per capita over the 10 year intervention. Most (96.0%) of the world’s adult population lived in countries in which this intervention had a cost effectiveness ratio <0.1×GDP per capita, and 99.6% in countries with a cost effectiveness ratio <1.0×GDP per capita. The intervention is projected to be highly cost effective worldwide, even without accounting for potential healthcare savings.


Thanks Dustin!