JMP专栏：UC-San Diego 第4期

为什么会有这个专栏？

有人曾问退休后的萨缪尔森：“能不能请您谈谈目前经济学研究的前沿是什么?”

萨翁答:“我不知道前沿在哪儿，如果我知道，我早就在哪儿了。这问题该去问我们的博士生。”

于是，我和小伙伴们在2023年底开启了一项“宏大”的计划，搜集整理美国经济系排名最靠前的10所高校博士生们的工作市场论文，这些论文一定程度上代表了经济学界的学术前沿。

后续，我们将每期推送3名候选人信息，直至全部候选人推送完毕。

本期是工作市场候选人信息第39期内容，也是UC-San Diego 第4期内容。

Stefan Faridani

University of California San Diego

Research interests

Econometrics, Development

Personal website

https://www.stefanfaridani.com/

Job market paper

Testing for underpowered literatures

How many experimental studies would have come to different conclusions had they been run on larger samples? I show how to estimate the expected number of statistically significant results that a set of experiments would have reported had their sample sizes all been counterfactually increased by a chosen factor. The estimator is consistent and asymptotically normal. Unlike existing methods, my approach requires no assumptions about the distribution of true effects of the interventions being studied other than continuity. This method includes an adjustment for publication bias in the reported t-scores. An application to randomized controlled trials (RCTs) published in top economics journals finds that doubling every experiment's sample size would only increase the power of two-sided t-tests by 7.2 percentage points on average. This effect is small and is comparable to the effect for systematic replication projects in laboratory psychology where previous studies enabled accurate power calculations ex ante. These effects are both smaller than for non-RCTs. This comparison suggests that RCTs are on average relatively insensitive to sample size increases. The policy implication is that grant givers should generally fund more experiments rather than fewer, larger ones.

Carlos Goes

University of California San Diego

Research interests

International Trade, Macroeconomics

Personal website

https://www.carlosgoes.com/

Job market paper

Trade, Growth, and Product Innovation

Can trade integration induce product innovation? I document that countries that joined the European Union (EU) started producing more product varieties, investing more in R&D, and trading more compared to candidate countries that did not join at a given horizon. Additionally, I show that a plausibly exogenous increase in market access increases the probability of a given country starting production of and exporting a given product. To rationalize this reduced-form evidence, I propose a new quantitative framework that integrates the forces of specialization and market size. This is a dynamic general equilibrium model of frictional trade and endogenous growth with arbitrarily many asymmetric countries that nests the Eaton-Kortum model of trade and the Romer growth model as special cases. Key results are analytical expressions to decompose: (a) gains from trade into dynamic and static components; and (b) growth and welfare into “Romer” and “Eaton-Kortum” parts. In this framework, the product innovation growth rate increases with higher market access. Finally, a quantitative version of the model suggests that: (a) the EU enlargement increased its long-run yearly growth rate by about 0.10pp; and (b) dynamic gains can account for between 65-90% of total welfare gains from trade.

Zachary Hall

University of California San Diego

Research interests

Applied Microeconomics, Behavioral Economics

Personal website

https://acsweb.ucsd.edu/~z1hall/Research.html

Job market paper

Inertia, Information and Enrollment Assistance: Evidence using Dominated Plan Choice in the California Individual Health Insurance Market

In 2018, a federal legal decision regarding the Affordable Care Act (ACA) individual market fostered a natural experiment during which premiums for health insurance plans with mid-tier coverage exceeded those with high-tier coverage for middle-to-high income enrollees. In California, this put over 35,000 individuals at risk of re-enrolling in a previously chosen plan that was now dominated by a lower-premium, higher-coverage plan. I study a clean case of inertia and other choice errors by examining choice of this plan throughout the state: 64.3% of these enrollees remain in the dominated plan. These inert individuals forgo at least 320 per full-year enrollee, though the actual consumer loss is larger for most enrollees and affects a larger subset of enrollees. I also examine how seeking help in the form of government or corporate (issuer-based) assistance interacts with this behavior. Overall, governmental help is associated with the lowest rates of inertia, though corporate assistance is marginally advantageous as well. No form of assistance fully or nearly eliminates these choice errors that are clear ex-ante. While current allocations of assistance resources slightly reduce outcome disparities along race and age dimensions, mandated assistance would not likely mitigate these disparities and could exacerbate those that exist along an income gradient. Still, universal uptake of these resources could reduce losses by over 30%. Finally, I find evidence that enrollees with low health insurance literacy are those who generally receive help; the causal effect of government help, thus, may be slightly underestimated.

供稿 | 翁煜晗

编辑 | 翁煜晗

审核 | 张毅