https://tiny-econometrics.com/learning Econometrics for marketing decisions, one case at a time. en Mon, 05 Oct 2026 00:00:00 GMT https://tiny-econometrics.com/learning/competitive-pressure/share-of-voice-missing-digital-spend https://tiny-econometrics.com/learning/competitive-pressure/share-of-voice-missing-digital-spend Mon, 05 Oct 2026 00:00:00 GMT Competitive Pressure A mattress brand read a 30% share of voice from monitoring data blind to digital. Three honest definitions gave three opposite answers. What to do instead. https://tiny-econometrics.com/learning/scenario-simulation/scenario-simulation-budget-shift https://tiny-econometrics.com/learning/scenario-simulation/scenario-simulation-budget-shift Mon, 05 Oct 2026 00:00:00 GMT Scenario Simulation What happens when a quarter of the budget moves from Meta to Google? How a fitted scenario simulation with uncertainty bands answers before you spend. https://tiny-econometrics.com/learning/baseline-forecast/baseline-forecast-one-off-shock https://tiny-econometrics.com/learning/baseline-forecast/baseline-forecast-one-off-shock Sun, 04 Oct 2026 00:00:00 GMT Baseline Forecast A pasta maker lost a customer worth 18% of volume. A baseline fitted across the break forecast a decline that was not there. Why, and how to rebuild it. https://tiny-econometrics.com/learning/budget-optimization/cost-per-grp-tv-return https://tiny-econometrics.com/learning/budget-optimization/cost-per-grp-tv-return Sun, 04 Oct 2026 00:00:00 GMT Budget Optimization Eight TV dayparts plotted by cost per GRP against return per euro. Learn why the most expensive GRPs return the least and how to plan the trade. https://tiny-econometrics.com/learning/price-elasticity/price-elasticity-five-per-cent-rise https://tiny-econometrics.com/learning/price-elasticity/price-elasticity-five-per-cent-rise Sat, 03 Oct 2026 00:00:00 GMT Price Elasticity A household-goods brand feared a 5% list-price rise. Elasticity -1.4 on relative price showed volume would hold if the rise travelled with the category. https://tiny-econometrics.com/learning/cross-elasticity/cross-price-elasticity-rivals https://tiny-econometrics.com/learning/cross-elasticity/cross-price-elasticity-rivals Sat, 03 Oct 2026 00:00:00 GMT Cross-Elasticity How cross-price elasticity and its confidence interval reveal which competitors actually take your volume and which only sit nearby on the shelf. https://tiny-econometrics.com/learning/trend-analysis/subscription-growth-before-marketing https://tiny-econometrics.com/learning/trend-analysis/subscription-growth-before-marketing Fri, 02 Oct 2026 00:00:00 GMT Trend Analysis A coffee subscription credited 4,080 new subscribers to its campaigns. The trend, held fixed, said 855 of them. The budget doubling did not happen. https://tiny-econometrics.com/learning/promo-elasticity/promo-elasticity-discount-volume https://tiny-econometrics.com/learning/promo-elasticity/promo-elasticity-discount-volume Fri, 02 Oct 2026 00:00:00 GMT Promo Elasticity How promotional semi-elasticity measures the volume a discount buys, why the response is a smooth curve and why uplift alone is not a verdict. https://tiny-econometrics.com/learning/lag-carryover/flat-spend-hides-carryover https://tiny-econometrics.com/learning/lag-carryover/flat-spend-hides-carryover Thu, 01 Oct 2026 00:00:00 GMT Lag & Carryover An insurer asked how long paid social keeps working. Seventy weeks of identical spend made adstock unmeasurable. What to run instead: pulses or a geo test. https://tiny-econometrics.com/learning/price-elasticity/price-elasticity-of-demand https://tiny-econometrics.com/learning/price-elasticity/price-elasticity-of-demand Thu, 01 Oct 2026 00:00:00 GMT Price Elasticity How to estimate price elasticity from weekly data with promotions and competitor prices controlled, and what an elasticity of -1.5 means for revenue. https://tiny-econometrics.com/learning/competitive-pressure/challenger-brand-excess-share-of-voice https://tiny-econometrics.com/learning/competitive-pressure/challenger-brand-excess-share-of-voice Wed, 30 Sep 2026 00:00:00 GMT Competitive Pressure A challenger oat drink brand spent above its share and grew. The pressure index by period showed most of the gain came in three quiet quarters. https://tiny-econometrics.com/learning/budget-optimization/budget-optimisation-same-budget https://tiny-econometrics.com/learning/budget-optimization/budget-optimisation-same-budget Wed, 30 Sep 2026 00:00:00 GMT Budget Optimization What a media budget optimiser recommends on the same total spend, and the three caveats to state before anyone quotes the modelled uplift. https://tiny-econometrics.com/learning/baseline-forecast/baseline-forecast-budget-target https://tiny-econometrics.com/learning/baseline-forecast/baseline-forecast-budget-target Tue, 29 Sep 2026 00:00:00 GMT Baseline Forecast A homeware retailer set next year at last year plus 8%. The business-as-usual baseline showed 3% was already in the trajectory. How that changed the plan. https://tiny-econometrics.com/learning/base-vs-incremental/base-vs-incremental-sales https://tiny-econometrics.com/learning/base-vs-incremental/base-vs-incremental-sales Tue, 29 Sep 2026 00:00:00 GMT Base vs Incremental How separating base sales from incremental sales shows what marketing added, and why every efficiency metric measures a mixture until you do. https://tiny-econometrics.com/learning/price-elasticity/price-elasticity-without-price-variation https://tiny-econometrics.com/learning/price-elasticity/price-elasticity-without-price-variation Mon, 28 Sep 2026 00:00:00 GMT Price Elasticity A premium coffee brand held one shelf price for three years and asked what a rise would cost. With no price variation there is no elasticity to estimate. https://tiny-econometrics.com/learning/contribution-decomposition/contribution-decomposition-price-vs-media https://tiny-econometrics.com/learning/contribution-decomposition/contribution-decomposition-price-vs-media Mon, 28 Sep 2026 00:00:00 GMT Contribution & Driver Decomposition A contribution chart that keeps negative drivers shows price removing almost as much revenue as media added. Learn why both belong on one chart. https://tiny-econometrics.com/learning/trend-analysis/one-trend-line-two-regimes https://tiny-econometrics.com/learning/trend-analysis/one-trend-line-two-regimes Sun, 27 Sep 2026 00:00:00 GMT Trend Analysis A crisps brand fitted one trend line to 78 weeks that held a national listing. The line averaged two businesses. Why it fails, and what to do instead. https://tiny-econometrics.com/learning/base-vs-incremental/how-much-marketing-added https://tiny-econometrics.com/learning/base-vs-incremental/how-much-marketing-added Sun, 27 Sep 2026 00:00:00 GMT Base vs Incremental The question every client asks once a year, answered as a split in euros: incremental revenue against base demand, with the statistics to check it. https://tiny-econometrics.com/learning/lag-carryover/outdoor-burst-judged-on-the-wrong-week https://tiny-econometrics.com/learning/lag-carryover/outdoor-burst-judged-on-the-wrong-week Sat, 26 Sep 2026 00:00:00 GMT Lag & Carryover A furniture retailer nearly cut an outdoor and radio burst that looked flat on week-of sales. Adstock showed most of the effect arrived after it ended. https://tiny-econometrics.com/learning/saturation-curves/saturation-curve-bend-interval https://tiny-econometrics.com/learning/saturation-curves/saturation-curve-bend-interval Sat, 26 Sep 2026 00:00:00 GMT Saturation Curves How a fitted saturation curve shows diminishing returns on TV spend, and why the interval around the bend matters more than the point estimate. https://tiny-econometrics.com/learning/lag-carryover/adstock-carryover-media-half-life https://tiny-econometrics.com/learning/lag-carryover/adstock-carryover-media-half-life Fri, 25 Sep 2026 00:00:00 GMT Lag & Carryover Media effects decay at different speeds by channel. Learn what adstock half-life is and why short reporting windows undervalue long-memory media. https://tiny-econometrics.com/learning/seasonality-event/seasonality-revenue-calendar https://tiny-econometrics.com/learning/seasonality-event/seasonality-revenue-calendar Thu, 24 Sep 2026 00:00:00 GMT Seasonality & Event Impact Month effects, weekday effects and dated events explain most of a retail series. Learn why campaigns must be judged net of seasonality. https://tiny-econometrics.com/learning/time-series/time-series-forecast-interval https://tiny-econometrics.com/learning/time-series/time-series-forecast-interval Wed, 23 Sep 2026 00:00:00 GMT Time Series (ARIMA) What a SARIMAX forecast of weekly installs teaches about memory, seasonality and why quoting the line without its band turns a range into a promise. https://tiny-econometrics.com/learning/baseline-forecast/baseline-forecast-business-as-usual https://tiny-econometrics.com/learning/baseline-forecast/baseline-forecast-business-as-usual Tue, 22 Sep 2026 00:00:00 GMT Baseline Forecast Why a Holt-Winters baseline forecast is the only fair benchmark for a campaign, and how it changes what a 6% revenue rise really means. https://tiny-econometrics.com/learning/trend-analysis/trend-analysis-structural-growth https://tiny-econometrics.com/learning/trend-analysis/trend-analysis-structural-growth Mon, 21 Sep 2026 00:00:00 GMT Trend Analysis How a fitted trend line separates the growth a business was always going to have from what campaigns added, with slope, R² and honest p-values.