UK → US

The most traveled route. The Comedy Store (1979), alternative cabaret, The Young Ones, The Day Today, Fast Show, and the Edinburgh Fringe all deposited techniques into US alt comedy: the deliberate hour, the conceptual run, absurdist sketch grammar. Stewart Lee's approach to audience provocation shows up later in Nanette-era Gadsby; Chris Morris's news parody anticipated Nathan for You by two decades. The current wave of British exports — James Acaster, Mae Martin, Rose Matafeo — arrives on US streamers fully formed because the Fringe functions as a 70-year R&D lab.

Australia → US/UK

A disproportionately productive scene. The Melbourne International Comedy Festival is the southern-hemisphere Fringe analog. Hannah Gadsby's Nanette was the highest-impact crossover of the streaming era; Sam Simmons, Zoë Coombs Marr, and Aunty Donna arrived via the same pipeline. Australian absurdist sketch (Aunty Donna, Hamish & Andy) has been especially legible to YouTube and now Netflix.

Canada → US

The Second City Toronto → SCTV → SNL pipeline is the original. Kids in the Hall set a template for sketch that permitted unreason. More recently: Mae Martin, Atsuko Okatsuka (Japanese-American via the Vancouver scene), Baroness von Sketch.

Japan → Everyone

Japanese manzai duos and owarai variety formats contributed the beat-structure and tempo that shows up in Tim and Eric's editing, and Gaki no Tsukai's endurance-comedy bits (the "Silent Library" format, the long annual specials) have a direct line to Nathan Fielder's durational pieces and to YouTube endurance comedy generally.

What Transfers and What Doesn't

Transfers well

Structural innovations (long-form, multi-part, character-in-context). Tempo. Absurdist premises. Physical sketch.

Transfers badly

Class-specific material. Topical political material. Anything that depends on knowing which TV presenter is being parodied.

Transforms in transit

Irony registers move across borders but shift: British understatement becomes American deadpan; Japanese surrealism becomes Adult Swim.