arXiv subjects

Piyush Akimitsu

Publications and source records attributed to Piyush Akimitsu.

4 recordsLinked to original sources

arXiv2026

Artificial Intelligence: Supply-Chain Chokepoints and the Reach of Industrial Policy

Artificial intelligence depends on a stack of inputs, models on compute, compute on chips, and chips on electricity and refined minerals. This paper measures the concentration of each layer on one scale, the Herfindahl-Hirschman Index (HHI), from cited and reproducible data. Three findings follow. First, concentration forms a clear gradient. It is modest downstream, where public and regulatory attention is heaviest and model usage and cloud fall below the 1{,}800 mark United States agencies treat as highly concentrated. It rises steeply upstream, where public discourse is sparse. There advanced packaging scores 8{,}100, leading-edge lithography reaches the ceiling of 10{,}000, and one country dominates the production or refining of several critical minerals, gallium near that maximum. Second, these upstream layers are chokepoints and a strategic vulnerability for the whole AI economy. Antitrust cannot reach them, because they lie in foreign or state hands. Contesting them falls to export controls and domestic industrial policy. Third, placing reserves beside refining shows the concentration is built rather than geological, a variable industrial policy can move. A rise in an upstream input's price barely changes the cost of the product built from it, because the input is only a small share of that cost. A chokepoint's threat is therefore the loss of the input itself rather than a higher price.

econ.GN↗

arXiv2026

Wrong and More Confident: A Field Experiment on Large Language Models Taking a Graduate Economics Exam

A red herring, an irrelevant passage added to a problem, corrupts a language model's reasoning and, through it, its final answer, while the form of the response survives untouched. The benchmark, called the Graduate Economic Reasoning Benchmark (GERB), is sixty graduate-level microeconomics problems, each a detailed setup with a verified final answer and a step-by-step reference solution. Each problem has two versions, one with the red herring and one without, and each of those is asked in two ways, one requesting an explanation and one not. This is a within-subject $2\times2$ factorial experimental design. Thirty-eight language models answer all four versions of every problem. The clean problems (the control group) are already hard, with the models answering under sixty percent correctly on average. The red herring lowers the probability of a correct final answer by 12.3 percentage points, about a quarter of the models' mean accuracy of 0.525. The damage is largest on the problems the model rates as easy. Reasoning ability confers no protection, as the red herring's effect does not differ detectably across models with and without reasoning ability. It does change how the failure looks, since a model with no reasoning mode repeats one wrong answer across waves while a reasoning model wavers. The red herring also leads a model to rate a problem as easier than its clean version, while answering it wrong more often. Although open- and closed-weight models reach the same accuracy, the open-weight models reach it at a substantially lower cost per correct final answer. The form of the response is preserved even as its substance fails. The model still produces an explanation (explanation given), the final answer still follows from the reasoning shown (coherence), and, in the aggregate, it remains the same across waves (consistency).

econ.GN↗

arXiv2025

Effects of Price Regulations on Service Utilization and Public Insurance Costs: Evidence from Telehealth Parity Laws

This study explores Telehealth Parity Laws (TPLs) and their heterogeneous treatment effects by policy type on outpatient utilization and Medicare costs, considering broadband and licensure infrastructure. State-specific legislative framings create varied Price (physician reimbursement) and Cost (consumer expense) control combinations within a quasi-experimental design. Partial equilibrium causal estimates reveal negligible impacts on Medicare enrollment, indicating that Medicare cost shifts stem purely from outpatient utilization changes. Broadband access correlates with increased preventable hospital stays but lower Medicare costs and enrollment. Additionally, the Interstate Licensure Compact increases enrollment among the aged and disabled, possibly addressing previously unmet demand for healthcare services.

econ.GN↗

arXiv2024

How Do Regulations and Technology Affect Service Allocation and Market Structure?

The paper estimates the effects of Price Controls and Cost Controls on healthcare service quantity and their role in spatial restructuring of physician market. Exploiting the quasi-experimental variation in regulatory-technological environment generated by telehealth parity laws and broadband internet, I find that for aggregate sample and metro areas, Price Floor has a conducive effect on service quantity and physician density, amplified progressively with broadband, and Price Ceiling, unfavorable at mean broadband, converges to the same conducive effect as broadband rises, while Cost Parity has an unfavorable effect, with a negative broadband gradient. For non-metro areas, Price Floor and Price Ceiling have conducive effect on service quantity and unfavorable effect on physician density, indicating efficiency gains.

econ.GN↗