Hello, I'm Leath
/leɪθ/ — rhymes with faith
I'm an economist working in regulatory finance at Smart DCC, the company running Britain's smart meter data network. Previously, I spent six years at the British Business Bank, where I helped secure over £1bn in government funding and led programmes that supported over a million businesses during the pandemic. I also serve as a Non-Executive Director at Wenta, a social enterprise supporting small businesses, and sit on the Council of the Society of Professional Economists.
I grew up in Austria, studied economics in Vienna and Nottingham, and now live in London. This site is where I share what I'm reading, thinking about, and working on. I'm interested in economics, regulation, business, language, history, and philosophy.
Explore
Projects
Practical tools, translations, Chrome extensions, and data dashboards — spanning family logistics, the Financial Times, YouTube, Letterboxd, used-car markets, and Soviet textbooks.
Latest Writing
Competition and Rivalry
The fire that never sleeps — and the question of whether we should let it burn
From Peter Thiel's contrarian take on monopolies to Girard's mimetic desire — an essay on competition across sport, philosophy, economics, and everyday life.
Projects
Things I've built — practical tools, translations, Chrome extensions, and data projects.
A week-by-week summer holiday planner for families in and around Walthamstow. KidSorted brings 47 local camps into one searchable directory with verified dates, prices, hours and free HAF places — then helps parents turn a shortlist into a complete six-week plan and budget.
What's in it
- Searchable local directory — filter camps by age, area, activity, funding, day length, price and confirmed 2026 dates
- Side-by-side comparison — shortlist options and compare hours, prices and food at a glance
- Six-week family planner — assign camps, annual leave or grandparents, total the cost and spot uncovered weeks
- Private by design — names and plans are saved only in your browser
Walthamstow & nearby
47 camps
HAF places
Budget planner
Browser-local data
What would one original S&P 500 share be worth today if every later stock split were reassembled? NeverSplit connects issuer-backed split histories, raw IPO share prices, market capitalisation, index weight and an attributed Kaggle history into one traceable research interface.
What's in it
- Original-share leaderboard — rank by market cap, S&P 500 weight, share price, split count, cumulative factor or reconstructed value
- Full constituent directory — search and sort 503 securities by company, ticker or sector
- Visible evidence states — source freshness, verified histories and unresolved data conflicts stay explicit
S&P 500
Corporate actions
Kaggle
Graph engineering
Mobile-first
For fifteen years, filmmakers, actors and musicians have been filmed picking favourites from the Criterion Collection's closet. I turned all 477 visits into a database of 7,360 picks across 1,658 films — enriched with Letterboxd and IMDb ratings — then built two things from it. A taste map links every guest to those they share films with, revealing nine communities of taste that map onto auteur canons (Varda, Cassavetes, Bergman… and a Godzilla cluster). A 52-week syllabus distils the data into an actual viewing plan.
What's in it
- The Shape of Taste — an interactive network of all 477 guests, coloured by community, click any for their picks and taste twins
- A Year in the Closet — 52 films, one a week, with progress tracking and pace planning
- Open dataset — the full guests / picks / films tables as CSV and SQLite
JavaScript
Canvas
Network analysis
Letterboxd
IMDb
A complete English digitisation of A.P. Kiselev's Arithmetic (1938 edition) — the standard Soviet mathematics textbook used across Russia for decades. Translated from Russian and formatted as a navigable web document with sidebar table of contents.
Contents
- Part I — Integers — numeration, four operations, divisibility, measures and weights
- Part II — Fractions — common fractions, decimal fractions, proportional quantities, percentages
- Appendix — counting devices, supplementary material, tables
Russian → English
HTML
Mathematics
An interactive value-for-money analysis of 499 used Škoda Octavias on sale at UK approved retailers. Two takes on the same dataset: a regression-residual ranking (v1) that flags cars priced below their predicted value, and a weighted-preference dashboard (v2) that lets you tune what matters — body, trim, fuel, gearbox, mileage, age, dealer location.
Versions
- v1 — Regression residuals — ranks cars by how far their price sits below the predicted value
- v2 — Weighted preference — tune your filters and weights interactively to find the best match
JavaScript
Regression
Used cars
UK market
A wider browser across the full Škoda UK used market, sourced from Marketcheck. Filter by model, trim, body, fuel, transmission, price, mileage, model year, and dealer/city — then layer on weighted preferences to surface what matters most.
JavaScript
Marketcheck
Used cars
UK market
A Chrome extension that brings back the classic Financial Times comment experience. The FT's current comment system collapses all replies by default, making it tedious to follow discussions. This extension lets you expand or collapse all comments with one click, or set it to auto-expand every time.
Features
- Expand All — instantly expand every comment and reply with one click
- Collapse All — collapse replies while keeping top-level comments visible
- Always Expand — toggle on to auto-expand comments on every FT article you visit
- Never Misses Late Comments — v2.3 keeps watching so auto-expand still arms when the comment widget loads long after the page, works on already-open tabs without a reload, and pauses politely in background tabs
JavaScript
Chrome Extensions API
Shadow DOM
MutationObserver
A Chrome extension that sorts your YouTube video tabs by duration — shortest videos on the left, longest on the right. Built for those moments when you have a dozen YouTube tabs open and only a few minutes to spare.
Features
- One-Click Sort — click the toolbar icon to instantly organise all your YouTube tabs
- Smart Duration Detection — uses multiple fallback methods to accurately detect video length
- Clean Organisation — YouTube videos sorted by length, other tabs moved to the right
- Ad-Proof & Group-Aware — v1.2 anchors durations to the video ID (a pre-roll ad can never skew the sort), keeps tab groups intact, measures sleeping tabs, and adds a keyboard shortcut plus right-click options
JavaScript
Chrome Extensions API
YouTube Data API
ISO 8601
A swipe-style interface and local profile database for Letterboxd (formerly Vypode). Browse films as a card deck — swipe to mark as watched, like, watchlist, or skip — while a local-only, searchable database of your watched history builds on your device. Actions happen in the background so you never leave the deck.
Features
- Swipe Deck — browse films as cards with mouse or keyboard controls
- Background Actions — rate, like, or watchlist films without leaving the deck view
- Auto-Advance — automatically moves to the next film after each action
- Auto-Next Page — when you finish a page of films, it loads the next page automatically
- Works Everywhere — popular films, decade browsing, genre pages, watchlists, and user lists
- Local Profile Database — sync your watched, liked, and watchlist collections into a local-only database, searchable by title, rating, and review text
- CSV Export — v6.2 exports your watched history in Letterboxd's official import format, so your local data is fully portable
Controls
- Mark as Watched — left zone or left arrow key
- Like — top zone or up arrow key
- Add to Watchlist — right zone or right arrow key
- Skip — bottom zone or down arrow key
JavaScript
CSS Animations
Chrome Extensions API
Letterboxd
Work in Progress In Progress
Things I'm actively building, writing, or training for. Some are close to launch, others are still taking shape.
Stripe Press Book Club
A reading community built around Stripe Press titles — 19 books on technology, economics, science, and civilisation, read across four seasonal quarters in 2026.