📈 Econ-First · Optimized for STEM

Smart Notes for Serious Learners

An economics-first notebook, optimized for STEM learning. Model markets, write LaTeX, embed graphs, and sketch diagrams — all in one place.

Supply & demandMarket modelsLaTeX mathDesmos graphingLive markets & newsPDF export

structnotes.io

Notes

Workspace

📁 Economics 2026

📄 Market Equilibrium

📄 Price Elasticity

📄 Consumer Theory

📄 Game Theory

📁 Econometrics

📄 OLS Regression

📄 Time Series

📁 Problem Sets

📄 PS1 – Welfare

Market Equilibrium & Consumer Surplus

In a perfectly competitive market, equilibrium occurs where quantity demanded equals quantity supplied. At the equilibrium price P*, all willing buyers and sellers are matched — there is no excess supply or demand, and total welfare (consumer surplus + producer surplus) is maximised.

Linear Supply & Demand

Assume linear functions for demand and supply:

Q^d = a − bP (demand, b > 0)

Q^s = c + dP (supply, d > 0)

Setting Q^d = Q^s → P* = (a − c) / (b + d) , Q* = a − b·P*

Supply & Demand Diagram

Demand (D)

Supply (S)

Consumer surplus

Producer surplus

Welfare Analysis

Consumer surplus (CS) is the area of the triangle above P* and below the demand curve — the total benefit consumers receive beyond what they paid. Producer surplus (PS) is the symmetric area below P* and above the supply curve. Together they form total social welfare:

CS = ½ · (P_max − P*) · Q* = ½ · (a/b − P*) · Q*

PS = ½ · (P* − P_min) · Q* = ½ · (P* + c/d) · Q*

W = CS + PS

Computing Equilibrium in Python

Using the example market Q^d = 100 − 2P and Q^s = −20 + 3P:

# Market parameters
a, b = 100, 2  # demand: Qd = a - b*P
c, d = -20, 3  # supply: Qs = c + d*P
# Solve for equilibrium
P_star = (a - c) / (b + d)  # P* = (100+20) / 5 = 24
Q_star = a - b * P_star   # Q* = 100 - 48 = 52
# Welfare calculation
P_max = a / b  # choke price (Qd=0)
P_min = -c / d # supply intercept (Qs=0)
CS = 0.5 * (P_max - P_star) * Q_star
PS = 0.5 * (P_star - P_min) * Q_star
print(f"P* = {P_star}, Q* = {Q_star}")
print(f"CS = {CS:.1f}, PS = {PS:.1f}, W = {CS+PS:.1f}")
# Output: P* = 24.0, Q* = 52.0
#         CS = 676.0, PS = 390.0, W = 1066.0

Price Elasticity of Demand

Elasticity measures the percentage change in quantity resulting from a 1% change in price. At the equilibrium point, the own-price elasticity is:

ε_d = (∂Q^d/∂P) · (P*/Q*) = −b · (P*/Q*)

In our example: ε_d = −2 · (24/52) ≈ −0.92 (inelastic, |ε| < 1)

Since |ε_d| < 1, demand is inelastic at this equilibrium — a 1% rise in price reduces quantity demanded by only 0.92%. This matters for tax incidence: with inelastic demand, more of a per-unit tax is borne by consumers than producers.

Tax incidence reminder: For a per-unit tax τ, the new equilibrium satisfies P_buyers − P_sellers = τ. The burden split is determined by relative elasticities: buyers bear fraction d/(b+d), sellers bear fraction b/(b+d).

🌐

Markets & News

WORLD CLOCK

🇺🇸 New York09:32

🇬🇧 London14:32

🇩🇪 Frankfurt15:32

🇯🇵 Tokyo22:32

MARKETS

S&P 500

7,354 ▲

WTI Crude

78.2 ▼

Gold

4,096 ▲

USD/EUR

0.877 ▼

NEWS

Markets edge higher as inflation cools

Yahoo Finance · 2h

Oil steadies after a volatile session

BBC Business · 3h

Tech leads gains on Wall Street

CNBC · 4h

LaTeX

math rendering

embedded calculators

diagram types

Live

markets & news

PDF

& DOCX export

🌐 Live Sidebar

The world,
beside your work.

A built-in sidebar keeps a live world clock, global market levels, and regional headlines right next to your notes — so you can track what matters without breaking focus or opening another tab.

🕑

World clock

Eighteen major business centres — New York to Tokyo — with live local time and an exchange-open indicator.

📈

Global markets

Major indices, commodities (oil, gold, gas, metals) and FX rates, refreshed continuously through the day.

📰

Regional news

Curated business headlines across Global, US & Canada, Europe, Asia, and Latin America — switch sources in a click.

🎯

All in one rail

Everything sits beside your notes — no extra tabs, dashboards, or logins to break your concentration.

🌐 WORLD CLOCK

🇺🇸 New York09:32

🇬🇧 London14:32

🇩🇪 Frankfurt15:32

🇯🇵 Tokyo22:32

📊 MARKETS

S&P 500

7,354 ▲

WTI Crude

78.24 ▼

Gold

4,096 ▲

USD/EUR

0.877 ▼

📰 NEWS

Markets edge higher as inflation cools

Yahoo Finance · 2h

Oil steadies after a volatile session

BBC Business · 3h

Tech leads broad gains on Wall Street

CNBC · 4h

🧠

Structure drives retention

Cognitive science research consistently shows that organising information — not just highlighting or re-reading — is what builds lasting understanding. When your notes, math, and references live in one structured workspace, studying becomes genuine learning.

What's inside

Everything you need to learn effectively

∑

First-class Math

LaTeX block and inline math via MathLive, function plotting, and embedded Desmos graphing and scientific calculators.

🌐

Markets & News

A live world clock for major business centres, global indices, commodities and FX, plus regional news — right beside your notes.

⌨

Code Blocks

Syntax-highlighted code with language detection. Great for STEM notes that mix theory with implementation.

🗂

Workspaces & Folders

Organise notes across subjects, projects, and courses. Structure drives retention.

✏️

Sketch & Draw

Freehand handwriting canvas, Excalidraw diagrams, and Mermaid flowcharts — all embeddable inline.

📤

Export Anywhere

One-click PDF and DOCX export. Share read-only links to individual notes without requiring an account.

Why StructNotes?

Notes that hold their shape

StructNotes is built on one idea — structure drives retention. Your models, math, diagrams, and references live together in a single, organised, economics-first workspace, so studying turns into genuine understanding instead of endless re-reading.

📈

Built for economics

Supply & demand, monopoly, Solow, the PPF and more are first-class interactive blocks — alongside LaTeX, Desmos and scientific calculators.

🗂

Everything in one place

Notes, models, diagrams, drawings, and a live markets & news rail — no tab-hopping to break your focus.

🎓

Optimized for STEM

Made for students and teachers who work in models, graphs, and equations — economics first, but at home across STEM.

About the Creator

Made by an educator, for learners

StructNotes grew out of hands-on teaching and a frustration with note tools that treat economics and math as an afterthought. It is an independent, self-funded project with a single goal: give serious learners a calm, structured place to model, graph, and reason.

Have feedback or ideas? I would love to hear from you.

Usage Disclaimer

Beta software — use at your own risk

🔑

Invite-only at this time. Creating an account currently requires an invite code — open sign-ups are closed while StructNotes is in early beta.

StructNotes is in active beta and under ongoing exploration. It is provided on an as-is, as-available basis with no warranties of any kind. By using it you accept that you do so entirely at your own risk.

Features, data formats, and behaviour may change, break, or be removed at any time without notice.
Do not rely on StructNotes as the only copy of important work — keep your own backups.
We make no guarantee of availability, data integrity, or that your notes will be preserved.
Nothing here is professional, financial, legal, or academic advice.
You are responsible for the content you create and for complying with your institution's policies.

Our Network