An agent-based model of the US college application process using real acceptance data
An agent-based simulation of the US college admissions cycle
This simulation models the full US college admissions process as it actually works — from high school seniors building their college lists through every application round, to colleges filling their freshman classes. Every student and every college is an autonomous agent following real-world rules.
Left panel — High schools. Each card shows the student population with a GPA histogram, SAT distribution, and archetype breakdown. Students are generated from school-type distributions (elite boarding, public magnet, day school, etc.).
Center canvas — The arc visualization. Each arc is one application. Watch arcs appear as rounds progress.
Right panel — Colleges. Each card shows the school's real acceptance rate, the seat progress bar filling up as students commit, and a live breakdown of the admitted cohort by round.
Bottom dashboard — Statistics. Tabs show acceptance rates vs. real benchmarks, yield rates, hook analysis, and outcome distributions by high school.
How college admissions actually works in the US
US college admissions is a multi-round, holistic process that runs from October through May of a student's senior year. It is not a pure meritocracy — academic stats matter enormously but are not the only factor.
Students take the SAT/ACT, build extracurricular records, visit colleges, and begin narrowing their list.
Students finalize their college list: typically 8-14 schools split across dream/reach/target/safety tiers.
Students submit their ED (binding) or EA/REA (non-binding) applications.
ED/EA decisions arrive. Students accepted ED must withdraw all other applications and commit.
Regular Decision applications due. Students rejected ED may apply EDII at a different school.
Regular Decision letters arrive. Students with multiple acceptances must choose by May 1.
Top colleges use holistic review — no single number guarantees admission or rejection.
The six rounds simulated and how they differ
| Round | Deadline | Decision | Binding? | Avg. ED Boost |
|---|---|---|---|---|
| ED | Nov 1-15 | Mid-Dec | Yes | 1.5x-3.3x |
| EA | Nov 1-15 | Mid-Dec | No | ~1.2x-1.5x |
| REA | Nov 1 | Mid-Dec | No, exclusive | ~1.5x |
| EDII | Jan 1-15 | Feb | Yes | 1.3x-2x |
| RD | Jan 1-Feb 1 | Late March | No | -- |
How colleges are classified in this simulation
| Tier | Schools | Accept Rate |
|---|---|---|
| HYPSM | Harvard, Yale, Princeton, Stanford, MIT | 3.6%-5% |
| Ivy+ | Columbia, UPenn, Brown, Dartmouth, Cornell, Caltech, UChicago, Duke | 3.8%-8% |
| Near-Ivy | Johns Hopkins, Northwestern, Vanderbilt, Rice, Notre Dame, Georgetown, CMU, WashU | 5%-12% |
| Selective | Emory, Tufts, BC, Williams, Amherst, Middlebury, Pomona, Swarthmore, Bowdoin, USC, NYU, Northeastern, ... | 6%-22% |
| LAC / Public Elite | UVA, UCLA, Michigan, UC Berkeley, Georgia Tech, UNC, Colby, Wesleyan, Hamilton, ... | 7%-27% |
| Selective Public | UIUC, UW-Madison, UW Seattle, Purdue, Virginia Tech | 39%-55% |
How students are generated and what their attributes mean
Each student is drawn from distributions calibrated to their high school type.
| Attribute | Range | Notes |
|---|---|---|
| Weighted GPA | 2.8-4.5 | Accounts for AP/IB difficulty |
| SAT Score | 900-1600 | Combined Math + Reading/Writing |
| EC Quality | 1-10 | Extracurricular strength |
| Essay Quality | 1-10 | Modeled essay strength |
How this simulation decides who gets in
Each application generates a composite score compared against a threshold. The algorithm uses Academic Index, EC/Essay scores, feeder bonuses, hook multipliers, round multipliers, and holistic randomness.
Non-academic factors backed by research
| Hook | Boost | Evidence |
|---|---|---|
| Donor | 4x | Harvard "Dean's List" ~42% admit rate |
| Athlete | 3.5x | Coaches' lists get ~90%+ admission |
| Legacy | 2.5x | Harvard legacy ~34% vs 6% baseline |
| First-Gen | 1.4x | Socioeconomic diversity adjustment |
What the numbers in the dashboard mean
Acceptance Rate, Yield Rate, ED Acceptance Rate, Middle 50% SAT, Hook Share, and per-school Ivy Rate are all tracked.
Key terms in college admissions
| Term | Definition |
|---|---|
| ED | Early Decision - binding early round |
| EA | Early Action - non-binding early round |
| REA | Restrictive Early Action - non-binding but exclusive |
| RD | Regular Decision - standard round |
| Hook | Non-academic admission advantage |
| Yield | % of admitted students who enroll |
| AI | Academic Index - standardized formula combining GPA and test scores |