Week 2: The 10g Metric: Standard Drinks as Economic Currency
Dismantling the public health framing of the standard drink to establish the ABV-to-Dollar Index equation and standardize our baseline currency.
Core reading: Standard Drink Equivalency Models in High-Volume Retail Environments (Quaye, Health Economics Quarterly, 2017).
The Lecture#
In Australia, a “standard drink” is legally defined as exactly 10 grams of pure alcohol. Outside of this classroom, that metric is deployed almost exclusively as a public health harm-reduction tool. In this course, we dispense with the sociological framing entirely. We recontextualize the 10-gram metric as our foundational economic currency; the exchange unit that allows us to compare wildly disparate retail categories.
A 4-liter cask of cheap wine and a 700mL bottle of premium gin are functionally incomparable on a volumetric level. However, by reducing both to their total yield of 10-gram alcohol units, we establish a flat, standardized economic landscape.
This lecture introduces the core algorithmic formula that underpins your entire semester: Cost per Standard Drink = Retail Price / ((Volume in mL * (ABV% / 100) * 0.789) / 10). The constant 0.789 represents the specific gravity of ethanol at standard room temperature. By standardizing the currency, we expose the massive pricing disparities engineered by taxation and retail markups.
Applied Computational Lab#
We rely strictly on calculated analysis. In this week’s lab, you will not use a spreadsheet. You will select one physical SKU of your choice and manually calculate its exact standard drink yield and its ABV-to-dollar index using a desktop calculator and a pen.
Use the ABV-to-Dollar Index Calculator widget on this page to verify your manual working. If your hand-calculated index differs from the widget’s output, your understanding of the specific gravity multiplier is flawed. You must master this formula on a single item before you attempt to automate it across 150 SKUs in your Week 9 Data Scraping Exercise.
Mandatory reading#
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Understanding standard drinks and drinking guidelines — Kerr & Stockwell, Drug and Alcohol Review 31(2), 2012, 200–205. This paper provides the empirical justification for our computational methodology. Kerr and Stockwell demonstrate that human consumers are fundamentally incapable of calculating standard drink equivalencies in their heads—over-pouring is the statistical norm, and providing percentage-ABV information on labels does not correct the cognitive deficit. This finding is exactly why this course rejects estimation in favor of algorithmic extraction.
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Australian guidelines to reduce health risks from drinking alcohol — National Health and Medical Research Council, 2020. This is the regulatory document that legally anchors the 10-gram definition for the Australian jurisdiction. Every calculation in this course rests on this specific framework. Read the primary definition, and pay close attention to the structural note that a “served drink” (e.g., a pub pour) is frequently disconnected from a “standard drink.” You will need to account for this discrepancy when modeling the physical logistics of your 50-Person Event Portfolio in Week 12.
Standard drinks, by serve
Ten grams of pure alcohol, in the units a bottle shop actually sells. Enter a volume and an ABV to add your own serve to four reference serves: Beer (375 mL, 4.8%); Wine (150 mL, 13%); Spirit nip (30 mL, 40%); Cask wine (250 mL, 11%).
The week 2 lab: First review
Before the lab#
Bring the standard-drink conversion and index value you computed in lab 1, and the one decision behind it you are least confident about — a rounding choice, a promotional price you weren’t sure whether to use, a product you guessed the ABV for.
In the lab#
Short demos of each student’s lab-1 numbers, then feedback aimed at the decision rather than the arithmetic. Idris works through one live example to demonstrate what “showing your working” should look like in practice: cask wine against the Wine Equalisation Tax.
The worked example. A four-litre cask returns a lower price-per-standard-drink than almost anything else on the shelf, for two compounding reasons. Bag-in-box packaging removes most of bottled wine’s glass and freight cost per litre, and the Wine Equalisation Tax is levied at 29% of wholesale value rather than per litre of alcohol — so a $2 wholesale cask returns only a few cents of tax per standard drink, while a bottle at ten times the wholesale price returns proportionally the same rate but a far higher absolute tax per standard drink sold. The example produces a genuine price-floor anomaly: an 80-standard-drink cask can legally retail for less than a 20-standard-drink case of beer. Weeks 3 and 4 cover both halves of this in full; the lab only uses it to show what a defensible worked answer looks like before your own numbers are checked against the same standard.
Required reading: Volumetric Taxation and the Australian Cask Wine Pricing Anomaly (Australian Tax Review, 2019)
Afterwards#
What leaves the lab is feedback on the one decision you brought, and a second worked example — cask wine and the WET — to check your own method against once weeks 3 and 4 cover the same ground in full. Nothing in this lab is graded, but the conversion it corrects is load-bearing for both the scraping exercise and the portfolio.
What you leave the lab able to do
Written so a reader can tell whether it has been met without asking you. The assessments assume it has.
- work from lab 1 is running — your standard-drink conversion and one computed index value
- you can name the one decision in that calculation you are least sure about
Teaching team
- Idris Fenn — tutor