Thomson Reuters IPSOS PCSI

The Thomson Reuters/Ipsos Great Britain Primary Consumer Sentiment Index (PCSI) tracks consumer attitudes toward the local economy, personal finances, savings and major investments. Ipsos, through its Public Affairs unit, runs it on the Global Advisor online survey. Thomson Reuters, Refinitiv and LSEG have acted only as distributors reporting it first.

It runs monthly from March 2010, with a baseline of 100 set in January 2010 as a calculation reference, not an optimism cutoff. It covers a national online sample of more than 1000 adults aged 16 to 74, weighted to Census demographics. It measures perceptions, not actual spending, savings or employment, and it is not official British statistics or the GfK gauge.

Fieldwork runs online for about two weeks spanning the end of the prior month and the start of the release month. Results appear once a month around the middle of the month, datelined Washington DC with no fixed time stated. Ipsos and the distributor publish them first. Each release shows the National Index and the four sub-indices with month and year point changes, plus rankings, charts and methodology.

Each month uses only its own data from March 2010 with no stated revision. Investors read it as a leading indicator for consumption through point changes from the prior month and prior year. It is linked to spending, car registrations, unemployment and credit demand. Moves of 2.0 points or more count as significant, with no stated buy or sell cutoff.

The monthly result reflects the aggregation of the four weighted sub-indices.

• Current Conditions: perceived current personal financial conditions.
• Expectations: personal and community outlook for the coming economy.
• Investment: comfort with major and other household purchases and confidence investing and saving for retirement or children's education.
• Jobs: current job security plus six-month outlook and six-month review for self, family and acquaintances.

In May 2015 (fielded April 24 to May 8, 2015) the headline rose 0.4 points from 54.9 to 55.3. Jobs rose 1.3 points from 65.7 to 67.0, and Expectations rose 0.4 points from 62.1 to 62.5. Investment fell 0.5 points from 47.6 to 47.1 while Current Conditions held at 45.6, showing the headline is an aggregation that no single part explains.

1. Benchmark: the scale is fixed at 100 in January 2010 as a calculation reference, not an optimism cutoff, with typical British readings far below it.
2. Answer buckets: replies are grouped into Top Box for reward and Bottom Box for penalty.
3. Reward and penalty: Shapley values set one reward and one penalty number for each of the 10 questions.
4. Magnitude and Importance: magnitude is reward minus penalty, and Importance, the final weight, is magnitude divided by total magnitude.
5. Box weights and question value: Top weight is reward divided by magnitude and Bottom weight is penalty divided by magnitude. Each question scores Importance times (Top weight times Top percent minus Bottom weight times Bottom percent), and their sum gives the headline.
6. Illustrative example: with assumed reward 60 and penalty 40, magnitude is 20, and if the total is 220 Importance is about 0.0909. Top weight is 3.0 and Bottom weight is 2.0. With Top Box 55 percent and Bottom Box 30 percent the question adds about 9.55 points.
7. Balancing and vintage: answers are weighted to Census demographics, with a sample of 1000 accurate to 3.5 points under the Bayesian credibility interval. Each month uses only its own data from March 2010 with no seasonal adjustment described, and the global average weights countries equally.