Swap Number

Pay Gap Case Study #8 – 33 London Councils – We Are One

November 18, 2025 By Nigel Marriott

I am breaking a golden rule of pay gap reporting in this article, I am benchmarking the 33 London Borough Councils on their gender pay gap data!

Before you gasp in horror, let me say straightaway the outcome of this article is complete vindication of this golden rule. Benchmarking of employer pay gap data is statistically worthless. Pay gap data of all kinds is inherently multivariate and cannot be reduced to one number league tables. The story I will tell of the 33 councils of London in 2024 proves this point in spades. In effect, none of the councils have a gender pay gap despite all of them publishing data to the contrary.

Pay Gap Case Study #7 – Does the Department for Work & Pensions have a Gender Pay Gap?

March 5, 2023 By Nigel Marriott

The Department for Work & Pensions (DWP) says for every £1 paid to the median man in March 2022, the median woman was also paid £1. In other words, their 2022 median gender pay gap using hourly pay was 0%. However, their Gender Swap Number per 1,000 employees for this date was +26 which immediately raises the question “Have the DWP made an error in their calculations like Cleveland Police did in 2017?” This was my first reaction which seems remarkable for an employer with 91,006 full pay relevant employees on a public sector pay scale and the largest pool of statisticians of any government department.

Pay Gaps #28 – Does the NHS Harm Gender Equality?

February 17, 2023 By Nigel Marriott

“We’re committed to Gender Equality!”

As we approach International Women’s Day next month, expect to see more and more employers saying something like this in their PR. It’s an easy statement to make but what does Gender Equality mean to them and you? To encourage employers to be clearer on what this means for them, I want to explore 6 possible definitions. Along the way, I show some definitions of gender equality in the UK are out of reach unless half a million women working for the NHS (National Health Service) are replaced by men.

Pay Gaps #23A – How long will it take to close your pay gap?

August 9, 2021 By Nigel Marriott

Five months ago, I introduced the gender swap number as a superior statistic to the median gender pay gap. Feedback from clients and others since then has confirmed my hope they would find it more intuitive to use and interpret. This encouraged me to call on Parliament to amend the UK gender pay gap legislation so that swap numbers could be published for employers with 250 or more employees. I now want to build on this by showing a couple of simple calculations that can turn a swap number into an estimate of how long it will take an employer to close its pay gap.