We argue that Arrow’s independence of irrelevant alternatives (IIA) condition is unjustifiably stringent because it rules out making a social welfare function sensitive to individuals’ preference intensities. Accordingly, we propose a modified version of IIA, MIIA, that is a necessary and sufficient relaxation of IIA for taking account of intensities. Rather than obtaining an impossibility result, we show that MIIA together with several other axioms (satisfied by virtually all voting rules and social welfare functions used in practice and studied in theory) uniquely characterizes the Borda count (sometimes called rank-order voting) as a social welfare function.

Governments use policy experiments to facilitate learning, but the nature and effects of these experiments remain unclear. We analyze China's policy experimentation since 1980—among the most systematic in history—and document three facts. First, most experiments exhibit positive sample selection. Second, local politicians exert excessive efforts during experiments that are not replicable during policies’ national rollout. Third, the central government is not fully sophisticated when interpreting experimentation outcomes. These facts suggest that policy learning may be biased and national policies may be distorted. Thus, while China’s institutions enable experimentation at an unparalleled scale, the complex political environments can also limit effective policy learning.

Government policy uncertainty affects irreversible decisions including technology adoption and exit. This paper quantifies uncertainty surrounding the Mercury and Air Toxics Standards (MATS). We estimate a dynamic oligopoly model for coal-fired electricity generators that recovers generators’ beliefs regarding future MATS enforcement. We develop the approximate belief oligopoly equilibrium concept, where players understand that their decisions impact aggregate market states. MATS enforcement created substantial uncertainty: the perceived enforcement probability dropped to 43%. Resolving uncertainty early would increase profits by $1.39 billion but also increase pollution costs by 0.652–1.776 billion. Had exit been unlikely, resolving uncertainty early would have decreased pollution

This paper studies the predictability of long-term unemployment (LTU) using rich administrative data from Sweden. We establish substantial heterogeneity in LTU risk across individuals, accounting for both observed and unobserved heterogeneity using a wide range of observable predictors and multiple-spell outcomes, respectively. We apply our prediction algorithm to study the dynamics of job finding over the unemployment spell and the business cycle. Selection effects can explain most of the decline in average job finding over the unemployment spell but little of its cyclicality. We also find sizable heterogeneity in the profiles of job finding over the unemployment spell but not over the business cycle

We estimate long-run trends in intergenerational relative mobility for representative samples of the US-born population. Harmonizing all surveys that include father’s occupation and own family income, we develop a mobility measure that allows for the inclusion of nonwhite individuals and women for the 1910s–1970s birth cohorts. We show that mobility increases between the 1910s and 1940s cohorts and that the decline of Black-white income gaps explains about half of this rise. We also find that excluding Black Americans, particularly women, considerably overstates the level of mobility for twentieth-century birth cohorts while simultaneously understating its increase between the 1910s and 1940s.