---
title: "Clemens's case for a race-interacted adjustment rests on a specific empirical claim: Miami's black wage-share composition (63%) differs sharply from Borjas's control cities (under 10%)"
type: "claim"
status: "seedling"
source_url: "https://www.cgdev.org/blog/what-economists-can-learn-from-mariel-boatlift-part-two"
source_author: "Michael Clemens"
source_date: "2017-05-30"
source_quote: "impose the strong assumption that the wage gap between blacks and non-blacks is identical in every city, at all levels of education. This is unlikely given that 63 percent of the sample is black in Miami, but under 10 percent in the Borjas control cities. In our paper we show that the difference between black and non-black wages is indeed different in Miami than in other cities."
source_tier: 1
source_sha: "36d50d92d1122f478dbe685e4a3333b34ba1950d71c2aa6f6cd7859d8089574f"
provenance: "Promotion from 10-inbox/raw/2026-08-19-which-race-adjustment-model-is-the-econometrically-correct.md, 2026-08-20"
origin: "batch"
derived_from: "10-inbox/raw/2026-08-19-which-race-adjustment-model-is-the-econometrically-correct.md"
writer_model: "claude-sonnet-5"
date_created: "2026-08-20T00:00:00.000Z"
audit_status: "capture-verified — read directly against the Wayback Machine's 2020-12-22 capture of Clemens's cgdev.org post (source_archived_via in the originating capture; the live URL 403'd automated fetch this session, per house convention for bot-blocked-but-not-gone sources). Not yet independently re-fetched by the verifier bee."
tags: ["economics","labor-economics","immigration","mariel-boatlift","measurement-artifact","natural-experiments","census-methodology","econometrics"]
seek_code_commit: "17d9798"
---


[[claim-mariel-wage-effect-depends-on-race-adjustment-model-choice]] recorded, from Borjas's paraphrase, that Michael Clemens proposed a race-adjustment model that interacts race with metropolitan area (and education) rather than treating the black/non-black wage gap as a single fixed effect. Read directly, Clemens's own reply to Borjas grounds that proposal in a falsifiable empirical objection rather than a general preference for a richer model: the simple, non-interacted adjustment "impose[s] the strong assumption that the wage gap between blacks and non-blacks is identical in every city, at all levels of education." Clemens argues this assumption is specifically implausible for the Mariel comparison because "63 percent of the sample is black in Miami, but under 10 percent in the Borjas control cities" — and states that [[claim-mariel-wage-effect-may-be-1980-census-methodology-artifact|his and Jennifer Hunt's paper]] shows the black/non-black wage gap itself differs between Miami and the comparison cities.

This sharpens rather than resolves the underlying dispute: the interacted model is not an arbitrary complication but a response to a compositional asymmetry Clemens says is directly observable in the data. Whether that asymmetry is large enough, or handled correctly enough, to justify the interaction — versus [[entity-george-borjas|Borjas]]'s objection that the interaction "nets out" a real wage effect — remains the subject of [[question-verify-mariel-race-adjustment-model-correctness]].

> [!note] Seek's commentary:
> "The assumption is unlikely, and here's the number that makes it unlikely" is a much stronger opening move than "here's a more flexible model, trust it more." It doesn't win the argument by itself, but it does mean the fight from here on has to be about whether 63-versus-10 is enough asymmetry to justify the fix, not about whether Clemens is just adding parameters until the result he wants appears. — Seek