Google Scholars


World Productivity: 1996-2014, joint with Bart Hobijn and John Fernald. (forthcoming American Economic Journal: Macroeconomics)

Online Appendix, Replication Files

Presented at Society for Economic Dynamics 2019.

Abstract: We use a new growth accounting method to quantify the drivers of world total factor productivity (TFP) growth during 1996-2014 and uncover four main results. World productivity growth is volatile from year to year. This mainly reflects the reallocation of labor across country-industries. The contribution of country-industry-level productivity growth to world productivity is relatively constant over time. This constancy masks that the increased importance of emerging economies offsets a productivity slowdown in advanced economies. After 2008, this offsetting effect dissipated, and the world TFP growth declined. These conclusions are robust to the inclusion of markups in the analysis.

Working papers

Investment in Skills, Managerial Quality, and Economic Development

Presented at Midwest Macroeconomics Meeting, Spring 2019.

Abstract: I document that for a group of 76 countries ranging from poor to rich: (1) the share of managers is lower in richer countries, (2) the share of skilled managers is higher in richer countries, and (3) the relative income of managers to non-managers is lower in richer countries. I explore these facts through the lens of a general equilibrium model of investments in skill and occupational choice. Countries differ in productivity level in production and the level of size-dependent distortions. Size-dependent distortions are quantitatively more important for cross-country income differences than productivity. The model produces a realistic skill premium across countries and endogenously generates lower managerial quality in poor countries.

Inequality Over the Life-Cycle: U.S. vs Europe

Presented at:

Abstract: I document that (i) the mean and dispersion of pre-tax labor earnings grow faster over the life-cycle in the U.S. than in some European countries; (ii) these facts are largely driven by individuals with at least a college degree. I study these differences in labor earnings inequality using a life-cycle model of human capital accumulation and elastic labor supply, which features non-linear taxation and a college choice and complementary investments during college. The model economy accounts for the differential mean earnings growth patterns of individuals with and without a college degree in the United States and the observed within-group inequality over the life cycle. I find that non-linear taxation significantly suppresses pre-tax earnings, and reduces college attendance, and investments during college. More generous subsidies and transfers for college exacerbate labor earning inequality. I find that differences in taxation and college subsidies alone account for 94% of the differences in mean earnings, and 80% of the differences in variance of log earnings over the life-cycle across the U.S. and European countries. To fully reconcile the model with data, the role of differences in initial conditions appears key. 

Normative Growth Accounting: The Distorted-Planner Approach, joint with Bart Hobijn and John Fernald.

Presented at:

Work in progress

Lifetime Earnings Inequality Across U.S. and Europe: Males, Females, and Households.
Subjective Expectations and Earnings Dynamics in the U.S.
Who Benefits From College Subsidies? A Cross-country Analysis.


2016- Teaching Mathematics in Seven Countries, 1st Edition. Meraat Educational Innovations Center, Tehran, Iran. (joint with Moharram Naghizadeh and Masoud HajiSeyedHosseiniFard)

This is a translation of a report by the National Center for Education Statistics, from English to Persian. The report is part of the TIMSS 1999 Video Study and consists of video lectures from 8th-grade mathematics classes recorded in 1999 to study best practices in teaching mathematics. The countries in the study are Australia, the Czech Republic, Hong Kong SAR, Japan, the Netherlands, and Switzerland. The statistical analysis in the book provides seven teaching signatures in teaching mathematics, and the videos provide actual practices of different teaching signatures. All the video lectures are subtitled in Persian. This book is used as a textbook in official educational degrees for teaching high school mathematics in universities in Iran.

The original book can be downloaded here for FREE.

2015- 70 Educational Indicators in 20 Countries, 3rd Edition. Meraat Educational Innovations Center, Tehran, Iran. (joint with Moharram Naghizadeh)

This is a collection of educational and national-level statistics. This book is part of the official teacher education in Iran as a resource for comparative teaching practices.