October DealsAmazon USOctober deal check: compare before you payAmazon US: current deals, useful picks and tech finds.Check DealsPC HealthRecommendedCrashes, freezes, slowdowns? Check your PC nowSpot repairable issues before they interrupt work.Check PCOctober DealsAmazon USDeal season is back - check today's better picksAmazon US: current deals, useful picks and tech finds.See Picks×
Skip to content
The Finance Base
The Money Desk · Blog
Re:

How to Calculate Price Elasticity in KNIME: A Grouped Log-Log Workflow

A KNIME workflow for estimating product-market price elasticities with grouped log-log regressions, including data checks, interpretation, and limits.
From TheFinanceBase Team5 min to read
Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

To estimate price elasticity in KNIME, fit a demand regression to the logarithm of quantity sold and price; in a log-log model, the coefficient on log price is the estimated elasticity. For separate estimates by product and market, group the data with a KNIME loop, run the regression within each group, and collect each coefficient with its group identifiers. Treat the result as an association unless your study design addresses factors that influence both prices and demand.

What price elasticity measures

Price elasticity of demand is the percentage change in quantity demanded associated with a percentage change in price. An own-price elasticity relates a product’s demand to that same product’s price. A cross-price elasticity relates one product’s demand to a different product’s price.

Own-price estimates are often negative in ordinary demand settings, but do not force that sign: report what the model estimates and investigate unexpected results. The interpretation depends on the variables, sample, and specification used.

Prepare the data before grouping

Each observation should align quantity sold and realized price for the same product, market, and time interval. Before modeling, reconcile currency, units, pack sizes, returns, discounts, and missing values. These are analytical choices rather than a canonical preprocessing recipe prescribed by KNIME’s cited materials.

What’s actually slowing this PC down?

Pick the symptom - the matching free tool is one click away.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
#1 Best Overall

Choose groups to match the question. For example, a product-country group can produce a separate estimate for each product in each market. Keep the time interval and relevant demand shifters visible in the data; grouping alone does not control for them.

  • Check that price and quantity refer to the same product and period.
  • Decide how returns, discounted sales, and pack-size changes affect the quantity and price measures.
  • For a log-log model, identify zero or negative price or quantity values: logarithms are not defined for them. Exclude such observations only with a documented rationale, or use a transformation justified for the data, and report the resulting sample.

Fit a log-log demand model

A simple own-price specification is:

ln(quantity) = intercept + elasticity × ln(price) + error

Under this specification, the coefficient on log price is the estimated own-price elasticity, conditional on the model. The European Commission’s decision in merger case M.5046 explains the interpretation: “As a result the regression coefficients are the elasticities – no further computations are required.” The statement applies to the log-log model described there, not to every regression coefficient or pricing model. The decision also discusses testing the functional form and comparing alternatives. Read the European Commission decision, section 4.1.2.

Run a separate regression for each product-market group in KNIME

A KNIME Community discussion describes a grouped pattern for collecting regression coefficients by Country and Product ID. It names Group Loop Start and Loop End; a follow-up describes using flow variables, Constant Value Column, or Variable to Table Column to restore group values. This is community guidance from 2018–2022, not a guarantee that node labels or behavior are unchanged in every KNIME version. Confirm the available nodes and their settings in your installation. See the KNIME Community discussion.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
Rank #3
  1. Choose the grouping columns. Set Country and Product ID, or the product and market fields appropriate to your analysis, as the group keys.
  2. Start the group loop. Use Group Loop Start to pass one group’s rows through the loop at a time.
  3. Fit the regression inside the loop. Prepare the logged variables and run the regression on the current group. Keep the log-price coefficient in the output.
  4. Preserve group identifiers. Ensure the output includes the country and product key for the coefficient. The community discussion mentions flow variables, Constant Value Column, or Variable to Table Column as ways to carry group values through the workflow.
  5. Collect the results. Use Loop End to combine the group-level outputs into a table. The resulting rows should identify the group, its coefficient, and any diagnostics you choose to retain.

Check node documentation in your installed KNIME version for exact configuration details: the cited community example establishes a workflow pattern, not a current, complete elasticity recipe.

Validate estimates before interpreting them

Check variation and sample size within each group

A regression cannot identify a price relationship within a group if price does not vary there. In a KNIME Community discussion about many group regressions, a user raised a problem with groups whose average selling price was constant; the suggested response was to calculate within-group price variance and exclude groups with zero variance. See the KNIME Community discussion.

Flag groups with zero price variance before fitting, and examine whether remaining groups have enough observations and meaningful variation. Report which groups were excluded. Do not present undefined or unstable coefficients as usable elasticities.

Test the model and its assumptions

Compare plausible specifications rather than assuming log-log is always best. The European Commission decision discusses both linear-demand and log-log forms and notes that analysts assess functional-form validity with statistical tests and alternative forms. Where data permits, test relevant demand shifters and compare results across reasonable time windows, validation samples, and grouping choices.

Free tools Windows power users keep installed

One-click scans. No signup required.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.
Best Value
Sale
Storytelling with Data: A Data Visualization Guide for Business Professionals
  • Wiley
  • Language: english
  • Book - storytelling with data: a data visualization guide for business professionals

Separate association from causation

Observed prices may change in response to expected demand, promotions, inventory, seasonality, competitor behavior, or product mix. Those same factors can affect sales, so a regression of historical quantity on price alone does not establish that changing the price caused the estimated change in demand. Without a design that addresses these confounders, describe the coefficient as an association, not a causal price effect. The KNIME sources cited here do not establish a causal identification method.

Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Support on Ko-Fi

Distinguish own-price and cross-price models

If the question is whether one product’s price affects another product’s demand, include the other product’s price in the demand specification and interpret its coefficient as a cross-price term. In a log-log model, coefficients on logged prices correspond to elasticities under that specification. The European Commission decision discusses a model including prices of other products and category expenditure. Which terms to include depends on the products, data, and question; do not treat a single-product regression as a cross-price analysis.

What KNIME’s price-optimization template does—and does not—establish

KNIME’s Price Optimization template describes work with historical sales and product data, competitor pricing, value-based and regression-based strategies, and comparisons of turnover and contribution margin. It is relevant context for pricing analysis, but the template page does not specifically claim to calculate price elasticity or provide the log-log recipe above. A price recommendation or price prediction is not, by itself, a causal elasticity estimate.

Quick Recap

SaleBestseller No. 1
SaleBestseller No. 2
Bestseller No. 3
Discovering Business Statistics Textbook
Discovering Business Statistics Textbook
Used Book in Good Condition
$25.00
SaleBestseller No. 4
SaleBestseller No. 5
Storytelling with Data: A Data Visualization Guide for Business Professionals
Storytelling with Data: A Data Visualization Guide for Business Professionals
Wiley; Language: english; Book - storytelling with data: a data visualization guide for business professionals
$15.74

Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

Leave a Reply

Your email address will not be published. Required fields are marked *

Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.

More post from the Money Desk

  1. The Money DeskBlogTheFinanceBase09 OCT 267 minMortgage Escrow FAQs: Taxes, Insurance, Shortages, and Refunds
  2. The Money DeskBlogTheFinanceBase09 OCT 265 minHow Mortgage Escrow Accounts Work and What Homeowners Pay For
  3. The Money DeskBlogTheFinanceBase09 OCT 265 minHow to Read a Stock Chart, Volume and Market-Cap Data
Recommended PC Tool
Recommended PC Tool
Crashes, No Sound, or Screen Glitches?Free driver scan
PC Slower Than It Used to Be?Free scan - under a minute

Two free Windows tools

One Free Minute Could Fix That PC

Before you go - each of these free tools takes about a minute and tackles what quietly slows a Windows PC down.

Special offer. View Outbyte info, uninstall instructions, EULA, and Privacy Policy.