Add stacked simulation for efficient multi-scenario analysis

.gitignore

@@ -159,4 +159,25 @@ temp/
 *.tmp
 
 # Streamlit
-.streamlit/
+.streamlit/
+
+# Web Application
+finsim-web/node_modules/
+finsim-web/frontend/node_modules/
+finsim-web/frontend/dist/
+finsim-web/frontend/build/
+finsim-web/frontend/.vite/
+finsim-web/frontend/coverage/
+finsim-web/backend/__pycache__/
+finsim-web/backend/*.pyc
+finsim-web/backend/.pytest_cache/
+finsim-web/backend/.coverage
+finsim-web/backend/htmlcov/
+finsim-web/**/*.log
+
+# Keep CSV files that are outputs
+settlement_analysis_results.csv
+settlement_confidence_summary.csv
+
+# Executed notebooks
+*_executed.ipynb

analyze_annuity_difference.py

@@ -0,0 +1,139 @@
+#!/usr/bin/env python3
+"""Analyze why Annuity A outperforms B and C at high confidence levels."""
+
+import numpy as np
+import pandas as pd
+
+# Settlement parameters
+TOTAL_SETTLEMENT = 677_530
+IMMEDIATE_CASH = 150_000  # What's left to invest after buying annuity
+
+# Annuity details
+ANNUITY_A_ANNUAL = 42_195  # Life with 15-year guarantee
+ANNUITY_B_ANNUAL = 48_693  # 15 years only
+ANNUITY_C_ANNUAL = 64_765  # 10 years only
+
+# Other income
+SOCIAL_SECURITY = 24_000
+
+print("=" * 80)
+print("WHY ANNUITY A OUTPERFORMS B AND C")
+print("=" * 80)
+
+print("\n1. ANNUITY STRUCTURE COMPARISON")
+print("-" * 40)
+print(f"Annuity A: ${ANNUITY_A_ANNUAL:,}/year FOR LIFE (with 15-yr guarantee)")
+print(f"Annuity B: ${ANNUITY_B_ANNUAL:,}/year for 15 years ONLY")
+print(f"Annuity C: ${ANNUITY_C_ANNUAL:,}/year for 10 years ONLY")
+print(f"\nAll scenarios keep ${IMMEDIATE_CASH:,} in stocks")
+
+print("\n2. THE CRITICAL DIFFERENCE: LIFETIME INCOME")
+print("-" * 40)
+print("After the guarantee period ends:")
+print(f"  • Annuity A: Still pays ${ANNUITY_A_ANNUAL:,}/year until death")
+print(f"  • Annuity B: Payments STOP after year 15")
+print(f"  • Annuity C: Payments STOP after year 10")
+
+print("\n3. INCOME ANALYSIS BY PERIOD")
+print("-" * 40)
+
+# Years 1-10: All annuities paying
+print("\nYears 1-10 (all annuities active):")
+print(f"  Total income with Annuity A: ${SOCIAL_SECURITY + ANNUITY_A_ANNUAL:,}")
+print(f"  Total income with Annuity B: ${SOCIAL_SECURITY + ANNUITY_B_ANNUAL:,}")
+print(f"  Total income with Annuity C: ${SOCIAL_SECURITY + ANNUITY_C_ANNUAL:,}")
+print(f"  → Annuity C provides ${(ANNUITY_C_ANNUAL - ANNUITY_A_ANNUAL):,} more/year")
+
+# Years 11-15: C stops
+print("\nYears 11-15 (Annuity C stopped):")
+print(f"  Total income with Annuity A: ${SOCIAL_SECURITY + ANNUITY_A_ANNUAL:,}")
+print(f"  Total income with Annuity B: ${SOCIAL_SECURITY + ANNUITY_B_ANNUAL:,}")
+print(f"  Total income with Annuity C: ${SOCIAL_SECURITY:,} (annuity ended!)")
+print(f"  → Annuity C loses ${ANNUITY_C_ANNUAL:,}/year of income")
+
+# Years 16+: Only A continues
+print("\nYears 16-30 (Only Annuity A continues):")
+print(f"  Total income with Annuity A: ${SOCIAL_SECURITY + ANNUITY_A_ANNUAL:,}")
+print(f"  Total income with Annuity B: ${SOCIAL_SECURITY:,} (annuity ended!)")
+print(f"  Total income with Annuity C: ${SOCIAL_SECURITY:,} (annuity ended!)")
+print(f"  → B and C must fund ${ANNUITY_B_ANNUAL:,}-${ANNUITY_C_ANNUAL:,} from portfolio")
+
+print("\n4. PORTFOLIO DEPLETION RISK")
+print("-" * 40)
+
+# Calculate required portfolio withdrawals after annuities end
+spending_need = 60_000  # Approximate sustainable spending level
+
+print(f"\nAssuming ${spending_need:,}/year spending need:")
+
+# Years 16+ for Annuity B
+years_16_plus_withdrawal_B = spending_need - SOCIAL_SECURITY
+print(f"\nAnnuity B after year 15:")
+print(f"  Needs from portfolio: ${years_16_plus_withdrawal_B:,}/year")
+print(f"  That's ${years_16_plus_withdrawal_B * 15:,} over 15 years (before growth)")
+
+# Years 11+ for Annuity C  
+years_11_plus_withdrawal_C = spending_need - SOCIAL_SECURITY
+print(f"\nAnnuity C after year 10:")
+print(f"  Needs from portfolio: ${years_11_plus_withdrawal_C:,}/year")
+print(f"  That's ${years_11_plus_withdrawal_C * 20:,} over 20 years (before growth)")
+
+# Annuity A
+withdrawal_A = max(0, spending_need - SOCIAL_SECURITY - ANNUITY_A_ANNUAL)
+print(f"\nAnnuity A (entire period):")
+print(f"  Needs from portfolio: ${withdrawal_A:,}/year or less")
+print(f"  Portfolio can grow with minimal withdrawals")
+
+print("\n5. THE MATH: WHY A WINS AT HIGH CONFIDENCE")
+print("-" * 40)
+
+print("\nStarting portfolio for all annuity scenarios: ${:,}".format(IMMEDIATE_CASH))
+
+# Simple analysis assuming 5% real returns
+real_return = 0.05
+years = 30
+
+# Annuity A: minimal withdrawals
+portfolio_A_simple = IMMEDIATE_CASH * (1 + real_return) ** years
+print(f"\nAnnuity A (minimal withdrawals):")
+print(f"  Portfolio after 30 years (5% real): ${portfolio_A_simple:,.0f}")
+
+# Annuity B: heavy withdrawals after year 15
+# Rough approximation
+portfolio_B_year15 = IMMEDIATE_CASH * (1 + real_return) ** 15
+annual_withdrawal_B = years_16_plus_withdrawal_B
+remaining_years = 15
+# Depletes quickly
+print(f"\nAnnuity B (heavy withdrawals after year 15):")
+print(f"  Portfolio at year 15: ${portfolio_B_year15:,.0f}")
+print(f"  Then withdrawing ${annual_withdrawal_B:,}/year")
+print(f"  → Depletes much faster, especially in down markets")
+
+print("\n6. KEY INSIGHTS")
+print("-" * 40)
+print("""
+1. LIFETIME PROTECTION: Annuity A provides income for life, B and C don't
+
+2. PORTFOLIO PRESERVATION: 
+   - Annuity A: Portfolio mostly grows (minimal withdrawals)
+   - Annuity B & C: Portfolio depletes rapidly after guarantees end
+
+3. SEQUENCE OF RETURNS RISK:
+   - Annuity A: Protected - annuity covers most spending needs
+   - Annuity B & C: Exposed - must withdraw heavily in years 11-30
+
+4. LONGEVITY RISK:
+   - Annuity A: Fully protected - payments continue for life
+   - Annuity B & C: Exposed - no income after guarantees expire
+
+5. AT 90% CONFIDENCE:
+   - Need to survive market downturns AND live a long time
+   - Annuity A's lifetime income is crucial for this scenario
+   - B and C fail when markets are bad AND you live past 80-85
+""")
+
+print("=" * 80)
+print("BOTTOM LINE:")
+print("Annuity A's LIFETIME income stream makes it superior for high-confidence")
+print("retirement planning, even though it pays less initially than B or C.")
+print("=" * 80)