Selected Price Indexes Review: 2024

Selected price indexes review: 2024 outlines changes we made to the selected price indexes (SPI) items and their relative weights as a result of the wider consumers price index (CPI) review. The changes have been implemented in Selected price indexes: January 2025.

Key changes

Within the food group:

• meal kits has been added to the basket
• spinach replaced celery
• the relative importance of the non-alcoholic beverages subgroup increased
• the relative importance of the fruit and vegetables subgroup decreased.

Within the alcoholic beverages and tobacco group:

• liqueurs (off licence) has been removed
• cocktails replaced ready-to-drink (RTD)'s (on licence)
• the relative importance of the alcoholic beverages subgroup increased
• the relative importance of the cigarettes and tobacco subgroup decreased.

About the SPI

The SPI measures monthly changes in prices that households pay for a selection of goods and services. Price change is measured by tracking the prices of individual items that make up a representative group of goods and services.

The SPI covers the following groupings:

• food - CPI food group
• alcohol and tobacco - CPI alcohol and tobacco group
• rentals for housing - basket item from the CPI housing group
• vehicle fuels - two basket items from the CPI transport group
• domestic and international air fares - two CPI classes from the CPI transport group
• accommodation services - one CPI subgroup from the CPI recreation and culture group.

Historically, the food price index (FPI) was Stats NZ's only monthly price index release. The rental price index (RPI) was added as a separate release in January 2019. In October 2023, FPI, RPI, and the additional items above were compiled into a single release - the SPI.

International best practice is for the wider consumer price index (CPI) to be reviewed and updated at least every five years, so it remains relevant. The SPI is reviewed and updated alongside the CPI. The latest CPI review was delayed by a year due to COVID restrictions postponing household economic survey (HES) data collection in the year to June 2022. However, the upcoming update to the CPI weights is still within the recommended five-year time frame.

The SPI covers approximately 45 percent (by weight) of the quarterly consumers price index (CPI) basket of goods and services. This proportion is based on the 2020 weights and will be updated in April 2025 when the CPI review results are released.

The SPI items

In the 2024 SPI review, we updated the relative importance of items within the suite of SPI items.

We include items in the wider CPI to ensure good representation across the subgroups, classes, and sections. We select more items for classes and sections with a relatively high variation in price change (where prices of items tend to move differently) and less for classes and sections with little variation (where prices move similarly).

For the SPI, a collection of indexes within the wider CPI structure, we apply the same rules as CPI to select items.

The food basket is organised into five subgroups, which break down into 14 classes, which in turn break down into 64 sections (17 of which are publicly available). Each section (for example, 'beef and veal') comprises items that are representative of that section.

As part of the 2024 review, we added two items to the food basket - spinach and meal kits. In contrast only one item, celery, was removed. We also consolidated basket items, reducing the number of basket items by two but not the number of prices collected. The net effect is a fall to 161 items in the FPI basket, down from 162.

The alcohol and tobacco basket is organised into two subgroups, and four classes. We added one item, cocktails (on licence), and removed two, liqueurs (off licence) and spirit-based drinks (on licence). This brought the total number of items to 27, down from 28.

Rent, vehicle fuels, air fares, and accommodation services had no basket changes.

Information sources

The main source of information for the 2024 SPI review was the 2022/2023 Household Economic Survey (HES). The survey ran from July 2022 to June 2023 and was completed by about 3,400 households. It collected information on what households spend on food, and other goods and services.

Household expenditure statistics: Year ended June 2023 has more information on the HES.

HES respondents tend to under-report expenditure on some goods and services (for example, alcohol and tobacco).

Large, infrequent purchases (for example, international flights) may not be reported frequently enough by the 3,400 households in the survey to provide accurate estimates of total household expenditure.

For these reasons, we complement HES data with information from other sources, including Stats NZ surveys, government administrative data, retail transaction data, supermarket scanner data, and information provided by businesses and government agencies.

Changes in relative importance

To show the relative importance of the SPI subgroups, we calculate the proportion of each input based on their share of total household spending on that SPI group. For example, for every $100 households spend on food about $15 is spent on meat, poultry, and fish. We estimate this spending using the HES and other data sources.

Figure 1 shows the relative importance of the food subgroups in the 2017 and 2020 FPI reviews, and 2024 SPI review. The 2017 expenditure weights were set in the September month, due to delays caused by the 2016 Kaikōura earthquake, the 2020 expenditure weights set in the June month, and the 2024 expenditure weights set in the December month, due to COVID related delays in the HES survey.

Figure 1

Figure 2 shows how the relative importance of the FPI classes have changed over the past three reviews (FPI and SPI).

Figure 2

Figure 3 shows the relative importance of the alcohol and tobacco classes.

Figure 3

Expenditure weight changes - Food group

While all five food subgroups showed growth in expenditure between June 2020 and December 2024, subgroups with the least expenditure growth lost some of their relative weight shares.

In relative terms, non-alcoholic beverages and grocery food increased, while fruit and vegetables; restaurant meals and ready-to-eat food; and meat, poultry, and fish fell.

Fruit and vegetables

The fruit and vegetables subgroup decreased 1.41 percentage points to 11.62 percent of total food expenditure between June 2020 and December 2024. Prices for the subgroup rose 18.2 percent, and expenditure increased 31.6 percent.

The vegetables class contributed the most to the expenditure decrease. Its relative share fell 1.89 percentage points to 6.32 percent between June 2020 and December 2024. Vegetable prices only rose 2.8 percent. Fruits relative weight rose from 4.82 percent to 5.30 percent, with prices up 44.5 percent.

Note that the relative weights for the 2024 review are based on the December 2024 month, compared with the June 2020 month in the previous review. Weights in the SPI are price updated each month. As fruit and vegetables are priced differently at different times of the year, their relative weights change across the year.

Meat, poultry, and fish

The meat, poultry, and fish subgroup's relative share decreased slightly from 15.06 to 14.95 percent from June 2020 to December 2024. Prices rose 19.0 percent over this period, and expenditure grew 46.4 percent.

Both the 'meat and poultry' and 'fish and other seafood' classes fell in relative share, down 0.08 percentage points and 0.03 percentage points respectively. Within the 'meat and poultry' class, 'pork' and 'preserved, prepared, and processed meat' increased in relative weight between June 2020 and December 2024, while 'beef and veal', 'mutton, lamb, and hogget', and 'poultry' fell.

Grocery food

The grocery food subgroup increased its relative weight from 34.43 percent in June 2020 to 34.67 percent in December 2024. Over the same period prices rose 24.2 percent, and expenditure grew 48.6 percent.

The relative importance for the 'bread and cereals' class fell slightly from 9.53 percent in June 2020 to 9.30 percent in December 2024. Prices rose 25.2 percent. 'Cakes and biscuits' relatively small increase in expenditure of 24.7 percent contributed the most to this fall in relative weight, slightly offset by a 94.8 percent increase in 'pastry-cook products' expenditure.

'Milk, cheese, and eggs' class level expenditure grew 37.4 percent between June 2020 and December 2024. Prices rose 26.6 percent over the same period. Its relative weight fell from 9.40 percent to 8.75 percent. While the eggs and yoghurt sections both increased in weight, the milk and cheese sections decreased.

'Oils and fats' gained 0.36 percentage points of its relative weight in the food group, up to 1.99 percent in December 2024. Expenditure grew 79.9 percent, and prices increased 48.4 percent.

The 'food additives and condiments' class level expenditure movement was up 46.5 percent. Prices rose 19.4 percent from June 2020. The relative importance for this class remained basically unchanged, falling just 0.02 percentage points.

The 'confectionery, nuts, and snacks' class saw a relative weight fall of 0.84 percentage points from 8.51 to 7.67 percent, with 'snack foods' the only section that rose in relative weight. Expenditure grew 33.0 percent, with prices increasing 17.8 percent.

The 'other grocery food' class showed an expenditure increase of 132.2 percent. Prices rose 22.8 percent over the same period. The result was a 1.61 percentage point increase in relative weight to 4.41 percent, up from 2.80 percent in June 2020. This increase was mostly due to adding meal kits to the basket. Excluding meal kits, the relative weight for 'other grocery food' would have been 3.28 percent.

Non-alcoholic beverages

The non-alcoholic beverages subgroup's relative weight increased by 1.71 percentage points, which brings it up to 11.95 percent of the total food group. There was expenditure growth of 72.1 percent, with prices increasing 19.9 percent between June 2020 and December 2024.

All classes in this subgroup increased in relative share except for 'soft drinks', which fell from 4.61 percent to 4.06 percent. Coffee had the largest increase, up 0.73 percentage points to 2.11 percent, followed by energy drinks, up 0.58 percentage points.

Figure 4

Restaurant meals and ready-to-eat food

The relative share for 'restaurant meals and ready-to-eat food' fell for the first time since 2011, down 0.42 percentage points between June 2020 and December 2024. 'Restaurant meals and ready-to-eat food' made up 26.81 percent of total food expenditure, down from 27.23 percent in June 2020. Prices increased 27.0 percent, and expenditure increased 45.2 percent from June 2020 to December 2024.

At the class level, 'ready-to-eat food' (up 53.0 percent) had higher expenditure growth than 'restaurant meals' (up 30.5 percent). As a result, 'ready-to-eat food' increased from 17.80 percent to 18.46 percent of the food group, while 'restaurant meals' decreased from 9.43 percent in June 2020 to 8.35 percent in December 2024.

Expenditure weight changes - Alcohol and tobacco group

Overall expenditure for the alcohol and tobacco group rose just 3.6 percent between June 2020 and December 2024, while prices increased 22.3 percent over the same period. This may indicate either a fall in volumes being purchased and/or consumers switching to alternate products or cheaper brands.

Alcohol saw an increase in its relative share of this group, with cigarettes and tobacco falling in weight. This shift is due to cigarette and tobacco expenditure falling rather than a rise in alcohol expenditure.

Alcohol

Alcoholic beverages relative share of the alcohol and tobacco group increased 9.40 percentage points, from 57.16 percent to 66.56 percent. Expenditure grew 20.7 percent from June 2020 to December 2024, while prices rose 16.7 percent over the same period.

Spirits and liqueurs expenditure, up 43.8 percent, was the most significant increase in this subgroup. Its relative share rose 5.90 percentage points, up from 15.20 percent to 21.10 percent. Off-licence expenditure contributed the most, up 4.31 percentage points, while on-licence expenditure made up the remaining 1.58 percentage points.

Expenditure on wine was up 14.1 percent, with prices rising 11.7 percent. Its relative share rose 2.02 percentage points from 19.99 percent to 22.01 percent. On-licence expenditure gained more than off-licence expenditure - the relative share for on-licence rose 1.37 percentage points, while off-licence rose 0.66 percentage points.

Expenditure on beer was up 10.6 percent, with prices rising 15.0 percent between June 2020 and December 2024. Its relative share rose 1.48 percentage points from 21.97 percent to 23.45 percent. Off-licence expenditure increased (2.70 percentage points), offset by a fall in on-licence expenditure (1.22 percentage points).

Cigarettes and tobacco

The cigarettes and tobacco subgroup expenditure decreased 19.1 percent from June 2020 to December 2024, leading to a relative weight decrease of 9.40 percentage points. Prices for the subgroup rose 29.8 percent over that time.

Expenditure for cigarettes decreased 20.1 percent. Its relative importance fell 7.14 percentage points, from 31.13 percent to 23.99 percent. Prices rose 31.6 percent over the same period.

'Other tobacco products' also decreased, down 31.7 percent. Its relative importance fell 3.82 percentage points from 11.21 percent to 7.39 percent. Prices increased 26.4 percent.

Expenditure on 'e-cigarettes and refills' on the other hand increased from June 2020 to December 2024, up 334.2 percent. Prices fell 5.2 percent for this class over the same period. Its relative importance increased 1.57 percentage points from 0.49 percent to 2.06 percent.

Expenditure weight changes - Rents, petrol, diesel, and air fares

Rents, petrol, diesel, and air fares are released as individual price series in the SPI as some items within their higher aggregation are not available monthly.

The upcoming CPI review, and corresponding paper, will include the full relative weightings for rents, petrol, diesel, and air fares.

Expenditure weight changes - Accommodation

The accommodation subgroup changed significantly between 2020 and 2024. The base 2020 weights for domestic and overseas accommodation were adjusted to account for the effect of COVID restrictions on travel. Annual weight updates were then applied as travel routes reopened, ending in a final weight update in June 2023.

Impacts of COVID-19 on the 2020 CPI re-weight has more information on the original weight adjustment.

Table 1 details the relative weights since 2020.

Regional expenditure

We collect SPI prices from 12 regional pricing centres: Whangārei, Auckland, Hamilton, Tauranga, Napier-Hastings, New Plymouth, Palmerston North, Wellington, Nelson, Christchurch, Dunedin, and Invercargill.

The 2024 SPI review used regional expenditure weights for five broad regions: Auckland, Wellington, rest of North Island, Canterbury, and rest of South Island.

Regional expenditure weights ensure that price changes at a regional level are accurately reflected in the SPI groups. For example, a price change in Auckland (which has 33.69 percent of the population and a regional food expenditure weight of 33.63 percent) would have nearly three times the effect on the food price index as Canterbury (which has 13.01 percent of the population and a regional expenditure weight of 12.81 percent).

Figure 5 compares the proportion of food and alcohol and tobacco expenditure in each region (2024 FPI weight) with the region's share of the New Zealand population, according to population estimates from Stats NZ.

Figure 5

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Upcoming publications

The CPI review will be implemented when the Consumer price index: March 2025 quarter is released on 17 April 2025.

CPI review tables will be released in advance, on 10 April 2025, followed by the full CPI review information paper on 24 April 2025.

The household living-cost price indexes (HLPI) review will be implemented when the Household living cost price indexes: March 2025 quarter is released on 1 May 2025.

HLPI review tables will be available on 1 May, followed by the full 2024 HLPI review paper, published on 8 May 2025.