The Misery Index was an indicator created in the 1970's as a shorthand to indicate the political weather. It's very simple: it's the unemployment rate added to the annual inflation rate.
Here's what the misery rate was in recent UK general elections:
1997 General Election
Unemployment May 1997: 7.2%
Inflation May 1997: 2.1%
Misery Index: 9.3
Outcome: Conservative government defeated, Labour elected
2001 General Election
Unemployment June 2001: 5.1%
Inflation June 2001: 1.9%
Misery Index: 7.0
Outcome: Labour re-elected
2005 General Election
Unemployment May 2005: 4.7%
Inflation May 2005: 1.9%
Misery Index: 6.6
Outcome: Labour re-elected
2010 General Election
Unemployment May 2010: 7.9%
Inflation May 2010: 2.5%
Misery Index: 10.4
Outcome: Labour government defeated, Conservative-LibDem coalition elected
2015 General Election
Unemployment May 2015: 5.6%
Inflation May 2015: 0.3%
Misery Index: 5.9
Outcome: Conservatives increase vote to win a majority
2017 General Election
Unemployment May 2017: 4.3%
Inflation May 2017: 2.7%
Misery Index: 7.0
Outcome: Conservatives lose majority, govern as minority government
2019 General Election
Unemployment Dec 2019: 3.9%
Inflation Dec 2019: 1.4%
Misery Index: 5.3
Outcome: Conservatives win 80-seat majority
The Misery Index appears to be an excellent predictor of election results. As I write this, unemployment is 3.9%, but inflation is 8.7%, giving a Misery Index of 12.6. That indicates a thumping defeat for the Conservatives if the election was held now. Rishi Sunak's hopes rest on getting inflation down to 2% by the next election.
Source for unemployment data: https://www.ons.gov.uk/employmentandlabourmarket/peoplenotinwork/unemployment/timeseries/mgsx/lms
Source for inflation data: https://www.ons.gov.uk/economy/inflationandpriceindices/timeseries/l55o/mm23
