Using SPSS “Compare Means”

Making short work of the category tabulations

Microsoft Excel Spreadsheet

• Have audit data on “top” of Excel workbook, or note the “tab” designation.

• First row becomes the variable labels• First column should be number assigned to

each supplier (0=private label)• Do all editing, corrections to this spreadsheet

—use PASW for analysis and minor formatting changes once all error are spotted.

Common Errors in the Audit Spreadsheet

• Duplications of a variable name in top row.• Negative gross margins—too high of cost estimated for

the SKU, some can be tolerated• Percent gross margins on private label items below

those for leading brands—double check this, it is possible, but very unlikely.

• Failure to include a number column in spreadsheet:– 0 for private label– 1 for leading supplier, 2 for second, etc.– This permits use of “Select Cases” command in PASW

SPSS“Housekeeping”

• File, Open, Data, to open Excel file (“Files of Type,” Excel *.xls)

• Common “error” is formatting of “percent gross margin.” Do this to 0 decimal places.

• Use the “Manufacturer Number” column for “Select cases” command in SPSS.

Select Cases

• “Data, Select Cases, If condition is satisfied”• All private labels coded “0” for “MNO”• All brands found at competing retailers =

1,2,3, 4,5.• Any brands not found at competing retailers,

not private label listed as “Others”• Select brands for analysis by using “If

conditions is satisfied “MNO <6”

PowerPoint Presentation

• Every student prepares an PowerPoint Presentation (Step 7, “Rollout the Result”)

• Groups must present a full presentation, showing they have met all the requirement

• Student working individually can present a partial presentation, but at least present two slides (1) showing the share of shelf space, and (2) showing either the share of gross margin dollars or mean % gross margin.

5 Stores

• In the Presentations, groups and individuals should select 5 stores which are the best for showing a difference in strategy (shares of shelf space given suppliers) or tactics (gross margins).

• Students can show:– Leaders at different stores– Different depth at stores (within chains too)– Different gross margins within and between stores

Using Compare Means

• Analyze, Compare Means, Means…• Dependent variables and independent

variables• Options—Means or Percentages?• Copy SPSS output and “paste special picture”

directly into an Excel spreadsheet• Copy and paste from an Excel spreadsheet

into PowerPoint presentation.

Required I: Share of Shelfspace

• Dependent variables: Use the facings variables for selected retailers.

• Independent variable: Manufacturer (first column)

• Change Options from Default (for each cell):– % of Sum (share of facings)– % of Total N (share of SKUs)– N=number of SKUs

Share of Shelfspace

• Favored “Brands:” %SKUs < % Shelfspace– Clue to Category Captain, if your share of facings is

greater than your share of SKUs, it’s a favorable position for the supplier

– Dominant brands: %SKUs > % Shelfspace, indicates the supplier is either being “held back” or trying gain shelf space by increasing depth

Required II: Share of Gross Margin Dollars

• Dependent variables: Use the gross margin dollars ($) variables for selected retailers.

• Independent variable: Manufacturer (first column)

• Change Options from Default (for each cell):– % of Sum (share of gross margins)– % of Total N (share of SKUs)– N=number of SKUs

Required III: Percent Gross Margin and Manufacturer

• Dependent Variable: Gross Margins Percents (%) from selected retailers

• Independent Variable: Number for Manufacturer (or MFR)

• Options: Mean• % of Total N (share of SKUs) and N

• Which suppliers provided highest percent gross margins—did these vary by different retailers?

Examining Mean % Gross Margins

• What variation do you see across retailers within the leading brands? What should it tell you about the prices?

• What do see regarding private labels, and unique brands?– If percent gross margins are lower on private label

items—what’s your interpretation?– If unique brands have a lower percent gross

margins and low dollar gross margins…

Interpreting Share of Shelfspace and Gross Margin by Manufacturer

• Prices (and gross margins) actions benefitting a supplier will be low, or below average.

• A supplier’s line with above average, or higher gross margins will be higher, or above average will benefit the retailer.

• Remember: these are the retailer’s gross margins—not the suppliers

Preparing for the Exam• Run these required three SPSS procedures on

your audit data:– Groups should select 5 stores that show that

reveal the greatest differences.– Does one manufacturer appear to be “in control”

of the category?– Which retailer shows the strongest interest in

private label? Does any retailer care about P/L?– Are there retailers whose action can’t be

understood without the volume data?