Source: student_yield_behavior.md
How admitted students make final enrollment decisions. Data compiled from NBER working papers, NACAC surveys, Common Data Sets, IvyWise/IvyCoach reporting, and institutional press releases (2023-2025 admissions cycles).
| College | Yield (Class of 2029) | Yield (Class of 2028) | Notes |
|---|---|---|---|
| MIT | 86.6% | 85.8% | Highest yield among all colleges |
| Harvard | 83.6% | 83.0% | Consistently 82-84% |
| Stanford | ~82% | 81.9% | Surpassed Harvard briefly in 2020 |
| Princeton | 75.4% | 72.0% | Rising trend, historically 65-72% |
| Yale | ~70% | 69.8% | Lowest HYPSM, but rising |
Cross-admit data (when students get into both):
Harvard vs Yale: 63% choose Harvard, 37% Yale
Harvard vs Stanford: 61% choose Harvard, 39% Stanford
Yale vs Princeton: 59% choose Yale, 41% Princeton
| College | Yield (Class of 2029) | Yield (Class of 2028) | Notes |
|---|---|---|---|
| UChicago | ~68% | 72% | High yield boosted by heavy ED |
| Brown | 73.1% | 67.3% | Strong rise |
| UPenn | ~67% | 67.9% | ED fills ~55% of class |
| Dartmouth | 70.9% | 63.7% | Significant rise |
| Cornell | 63.6% | 68.4% | Variable year to year |
| Columbia | 61.3% | 67.1% | Declining trend |
| Duke | 57.3% | ~53% | ED fills ~50% of class |
| Northwestern | 57.7% | ~55% | ED fills ~55% of class |
| Caltech | 58.6% | 61% | Small class amplifies variation |
| College | Yield (Class of 2029) | Yield (Class of 2028) | Notes |
|---|---|---|---|
| Notre Dame | ~55% | 62% | High alumni loyalty drives yield |
| Johns Hopkins | 51.4% | ~40% | Variable, rising |
| Georgetown | ~47% | ~47% | Stable |
| Vanderbilt | ~47% | ~47% | Heavy ED reliance |
| Carnegie Mellon | 46.8% | 47% | Record high in 2024 |
| WashU | ~45% | 47% | ED-dependent |
| Rice | 42.8% | 44% | Smaller pool |
| College | Yield (est.) | Notes |
|---|---|---|
| UCLA | ~50% | High for public; in-state preference |
| Tufts | ~46-50% | "Tufts syndrome" / yield protection debate |
| Boston College | 45.1% | Strong Catholic/alumni network |
| UC Berkeley | ~44% | Similar to UCLA |
| Emory | 37.3% | Declining from ~40% |
| UVA | ~38% | Public flagship, in-state boost |
| Michigan | ~38% | Public flagship |
| USC | ~37% | Rising |
| College | Yield (Class of 2029) | Notes |
|---|---|---|
| Bowdoin | 53.8% | Highest LAC yield |
| Williams | ~47% | Strong brand |
| Middlebury | 42.0% | Typical for top LACs |
| Amherst | ~39% | Lower despite high prestige |
| Tier | Yield Range | Midpoint for Model |
|---|---|---|
| HYPSM | 70-87% | 80% |
| Ivy+ | 55-73% | 63% |
| Near-Ivy | 40-62% | 48% |
| Selective | 35-50% | 42% |
| Top LACs | 35-54% | 44% |
| National average (all 4-year) | ~30% | 30% |
Institutional prestige / academic reputation -- The single strongest predictor at the selective tier. Cross-admit data shows students almost always choose the higher-prestige option.
Financial aid / net cost -- The dominant factor outside the top 20. For families with income <$150K, net price is often the decisive factor. Research consensus: $1,000 additional aid increases enrollment probability by 2-4 percentage points.
Program/major strength -- Students choosing MIT over Harvard often cite STEM program depth. Engineering-focused admits favor Caltech, MIT, CMU, Stanford.
Location / geography -- 47% of students rank location as a top campus factor (BestColleges 2023). Students prefer staying closer to home on average, though prestige overrides distance for elite institutions.
Campus culture / student life -- Student quality of life (38%), campus safety (33%), diversity, and social scene all factor in.
Financial aid type (merit vs need) -- Merit scholarships carry a psychological "scholarship effect" beyond their dollar value. Students feel "chosen" by merit aid in ways need-based aid does not replicate.
Weather / climate -- Surprisingly ranked in top 10 by EAB 2024-25 survey. May explain Stanford/Duke/Vanderbilt appeal vs Northeast competitors.
Family influence -- Parent preferences, legacy connections, and sibling attendance patterns.
Campus visit experience -- Admitted student weekends have measurable yield impact (see Demonstrated Interest section).
Peer effects -- Where friends/classmates are going, guidance counselor recommendations.
| Factor | Low income (<$60K) | Middle ($60-150K) | High (>$150K) |
|---|---|---|---|
| Net cost | Dominant | Very high | Moderate |
| Prestige | High | High | Dominant |
| Location | High (stay close) | Moderate | Low (will travel) |
| Program fit | Moderate | High | High |
| Campus feel | Low | Moderate | High |
Dynarski & Scott-Clayton (2013) consensus estimate:
$1,000 additional aid increases enrollment by 2-4 percentage points
Effect is larger for lower-income students
Effect is larger for grant aid vs loan aid
Cal Grant program natural experiment:
1.2 to 9.2 percentage points per $1,000, depending on crowd-out assumptions
Wide range reflects methodological differences
DC Tuition Assistance Grant:
Research on selective colleges shows important nuances:
Threshold effect: The jump from $0 to any scholarship matters more than the dollar amount. A $5,000 scholarship can have nearly the same yield effect as $15,000 at some institutions.
Diminishing returns at elite tier: At HYPSM, financial aid has minimal yield impact because (a) most admitted families qualify for need-based aid already, and (b) prestige dominates decision-making.
Maximum impact zone: $10K-25K merit awards at Ivy+ through Selective tier schools show the largest yield effects.
| Tier | Yield change per $10K aid | Notes |
|---|---|---|
| HYPSM | +1-3% | Prestige dominates; most families already receive aid |
| Ivy+ | +3-6% | Moderate sensitivity |
| Near-Ivy | +5-10% | Sweet spot for merit aid leverage |
| Selective | +8-15% | Merit aid is a primary enrollment tool |
| National avg | +15-25% | Aid is often the deciding factor |
For the college-sim model, financial aid primarily matters at the student decision phase (yield), not the admissions phase. The model should apply a yield modifier based on the gap between a student's expected family contribution and the college's net price, with diminishing sensitivity at higher-prestige tiers.
Do NOT track demonstrated interest (yield already high enough):
All HYPSM schools
Most Ivies (Harvard, Yale, Princeton, Columbia, Brown, Dartmouth, Cornell)
Stanford, MIT, Caltech, UChicago
DO track demonstrated interest (need yield management):
Vanderbilt, Georgetown, Emory, Tufts, Boston College, Tulane
WashU, Carnegie Mellon, Lehigh, American, GWU
Many schools in 20-50% acceptance rate range
Lehigh University study:
In-person campus visit increases admission likelihood by ~30%
Costlier signals (travel to campus) have greater impact than low-cost signals (email open)
Effect is strongest at schools with 20-40% acceptance rates
NACAC data:
16% of colleges rate demonstrated interest as "moderate" or "considerable" importance in admissions
More common factor at less selective institutions
Signal hierarchy (strongest to weakest):
ED is effectively the strongest form of demonstrated interest because it guarantees 100% yield:
| School | % of class filled via ED | ED acceptance rate | RD acceptance rate |
|---|---|---|---|
| Northwestern | ~55% | ~25% | ~5% |
| Duke | ~50% | ~18% | ~4% |
| Vanderbilt | ~45% | ~20% | ~6% |
| Cornell | ~40% | ~17% | ~7% |
| Brown | ~40% | ~14% | ~5% |
| Dartmouth | ~40% | ~18% | ~5% |
| UPenn | ~55% | ~15% | ~5% |
Demonstrated interest should function as a yield predictor, not an admissions factor, for HYPSM/Ivy tier. For Near-Ivy and Selective tiers, it should boost both admission probability and yield probability.
| Tier | Avg % admitted from waitlist | Range | Notes |
|---|---|---|---|
| HYPSM | 0-5% | 0-16% | Princeton: 0.15% (low) to 16.4% (high) |
| Ivy+ | 2-8% | 0-15% | Dartmouth avg: 4.1% over 21 cycles |
| Near-Ivy | 5-15% | 0-25% | More variable |
| Selective | 10-25% | 0-40% | Higher acceptance rates |
| National avg | ~20% | varies |
| Period | Activity |
|---|---|
| April 1-May 1 | Students receive waitlist offers; must accept spot on waitlist |
| May 1 | National Candidates Reply Date -- deposits due |
| May 1-10 | Biggest burst of waitlist admissions (colleges learn actual yield) |
| May-June | Rolling waitlist admissions continue |
| Late June | Most colleges close waitlists |
| July-August | Rare late waitlist movement (melt) |
Students must deposit at another school while waiting (deposit typically $200-500)
50-80% of waitlisted students choose to remain on the waitlist
Students admitted from waitlist have slightly lower yield than regular admits (~60-80% accept)
Waitlist admitted students receive less favorable financial aid packages on average
Waitlist mechanics should model: (1) a percentage of under-yield spots filled from waitlist, (2) waitlist admits have lower yield than direct admits, (3) the waitlist pool is drawn from borderline-admit students.
yield_probability = base_yield[tier] * prestige_factor * aid_factor * round_factor * interest_factor * random_noise
base_yield[tier] -- Starting yield probability by college tier:
| Tier | Base Yield |
|---|---|
| HYPSM | 0.80 |
| Ivy+ | 0.63 |
| Near-Ivy | 0.48 |
| Selective | 0.42 |
| Top LACs | 0.44 |
prestige_factor -- Adjustment when student has multiple admits:
If this is the student's highest-prestige admit: 1.2x
If this is a lower-prestige option: 0.6x
If prestige difference is small (same tier): 1.0x
aid_factor -- Financial aid modifier:
aid_gap = expected_family_contribution - college_net_price
if aid_gap > 0: # college is cheaper than expected
aid_factor = 1.0 + (aid_gap / 50000) * tier_sensitivity
else: # college costs more than expected
aid_factor = 1.0 + (aid_gap / 50000) * tier_sensitivity
Where tier_sensitivity:
| Tier | Sensitivity |
|---|---|
| HYPSM | 0.10 |
| Ivy+ | 0.25 |
| Near-Ivy | 0.40 |
| Selective | 0.60 |
round_factor -- Admission round impact on yield:
| Round | Factor | Rationale |
|---|---|---|
| ED | 1.00 (forced) | Binding; yield = 100% |
| EA/REA | 1.05 | Slight boost from early engagement |
| EDII | 1.00 (forced) | Binding; yield = 100% |
| RD | 1.00 | Baseline |
| Waitlist | 0.75 | Lower yield from delayed admits |
interest_factor -- Demonstrated interest (Near-Ivy and below only):
| Interest Level | Factor |
|---|---|
| High (visited + ED) | 1.15 |
| Medium (visited or emailed) | 1.05 |
| Low/None | 0.95 |
| N/A (HYPSM/Ivy+) | 1.00 |
random_noise -- Uniform +-15% to capture unpredictable personal factors:
random_noise = 0.85 + Math.random() * 0.30 // range [0.85, 1.15]
When a student has multiple admits (non-binding rounds), they should:
yield_probability for each admitted collegeED/EDII admits: Student enrolls with 100% probability (binding)
Single admit: Student enrolls with 95% probability (5% gap year/other)
All waitlist: Student deposits at safety, then waitlist yield model applies
No admits: Student goes to unnamed safety school (exits simulation)
The model should produce aggregate yield rates within 5 percentage points of actual data:
HYPSM average yield: 78-84%
Ivy+ average yield: 58-68%
Near-Ivy average yield: 43-53%
Selective average yield: 37-47%
NBER Working Paper 10112: Financial Aid and Students' College Decisions
NBER Working Paper 15387: Dynarski on Student Aid and Enrollment
NBER Working Paper 30275: College Costs, Financial Aid, and Student Decisions
ScienceDirect: Impact of Merit-Based Financial Aid on Enrollment
Scholarships360: Demonstrated Interest in College Admissions