Exercises: The Guest List
Difficulty guide: ⭐ Foundational (5–10 min) · ⭐⭐ Intermediate (10–20 min) · ⭐⭐⭐ Challenging (20–40 min) · ⭐⭐⭐⭐ Advanced (40+ min)
This is the most quantitative chapter in Part I. Do the arithmetic by hand at least once.
Part A: Conceptual Understanding ⭐
A.1. Name the three cost categories and give three examples of each. For each category, state in one sentence how it responds to adding one guest.
A.2. Explain, to a client, why the "average cost per guest" is the wrong number to use when deciding whether to invite eight more people.
A.3. A colleague says: "Steps are a technicality — over a whole wedding it averages out." Give the strongest version of their claim, then explain what it misses.
A.4. Why does the Owner column make cutting possible? What conversation happens without it?
A.5. Explain the difference between forecasting attendance and setting the guaranteed count. Why are they different numbers, and which one costs money?
A.6. Why is under-forecasting worse than over-forecasting? Give two industry conventions that reflect this asymmetry.
A.7. Define without looking back: step threshold, marginal guest, list architecture, guaranteed count, the reciprocity trap.
A.8. State the rule that makes any plus-one policy defensible, and explain why guests object to what they object to.
Part B: Applied Analysis ⭐⭐
B.1. Classify twenty lines. For each, mark fully variable / step / fixed, and where it is a step, state the step size: chiavari chairs · officiant fee · dance floor · napkins · videographer · bartenders · cake · restroom trailer · ceremony arch floral · shuttle buses · place cards · DJ · wine · generator · escort card table · servers · marriage license · valet attendants · welcome bags · tent
B.2. Build a step map. For a 140-guest wedding at a venue with: 8-person rounds, one server per 20 guests (plated), one bartender per 75, restroom brackets at ≤100/≤150/≤200, and 32-seat shuttles. Identify every threshold from 100 to 200 and the cost of crossing it. Use plausible local pricing and state your assumptions.
B.3. Marginal cost, three points. Using your step map from B.2, compute the marginal cost of the 121st, the 145th, and the 152nd guest. Explain the difference to a client in three sentences.
B.4. Find the smallest cut. A couple is at 168 guests and $4,600 over. Catering is $88/head plus 24% service charge and 8% tax. Bar is $26/head. Their step map has crossings at 160 (bartender, $340), 152 (restroom bracket, $850), and 150 (second shuttle, $480), plus a table every 8 guests at $135 all-in.
- (a) What does the naive per-head calculation say?
- (b) What is the actual smallest cut that closes the deficit?
- (c) What is the difference in names, and what is that difference worth to the client emotionally?
B.5. Forecast a real list. Take a plausible 160-person list. Categorize it into the nine categories in §5.6, apply attendance rates, and produce an expected count with a range. Then state what you would guarantee and why.
B.6. Allocate a cut. A couple must cut 24 names. Current ownership: Partner A 71, Partner B 44, A's parents 38, B's parents 19. Produce the allocation three ways — proportional, equal, and contribution-weighted (A's parents are paying $18,000, B's parents $4,000, the couple $22,000). Which would you recommend and how would you present the choice?
B.7. Price three plus-one policies. For a 140-guest wedding with 28 single guests and the step map from B.2: compute the cost of universal plus-ones, wedding-party-only plus-ones, and cohabiting-partners-only. Present the three as you would to a client.
Part C: Real-World Application ⭐⭐–⭐⭐⭐
C.1. Build a real step map. ⭐⭐⭐ Pick an actual venue in your market. Get their capacity tiers, table configuration, and staffing ratios. Get real rental pricing for tables, linens, and restroom trailers. Build the complete step map from 80 to 250 guests. This is a market asset — you will reuse it for every client at that venue.
C.2. The guest list template. ⭐⭐ Build it with all five columns plus RSVP tracking, meal choice, dietary, and table assignment. Make it something you could hand a client that they would not immediately break.
C.3. Attendance archaeology. ⭐⭐⭐ Find three people who have been married in the last five years. Ask each: how many did you invite, how many came, and which category surprised you? Compare to §5.6's table. Where does your local market differ?
C.4. Ask the coworker question. ⭐ Ask five employed people: "If you left your job next month, which of your colleagues would you still see?" Note how many names they give and how long they take. What does this tell you about the coworker category?
C.5. Policy drafting. ⭐⭐ Write your plus-one, children, and coworker policies in three forms: as you would say them to a client, as they would appear on a wedding website, and as you would respond to a guest who emails asking for an exception.
C.6. The cut conversation, rehearsed. ⭐⭐ Write and then say aloud the full cut conversation: the number, the allocation, and your responses to the four most likely objections ("I can't cut my mother's list," "these are all people we have to invite," "can't we just find the money somewhere else," "you cut yours first"). Say it until it does not sound like a script.
Part D: Synthesis and Critical Thinking ⭐⭐⭐
D.1. Cross-chapter integration. Chapter 4's forced ranking says what gives when money is short. This chapter says guest count is the lever that moves everything. Construct the decision procedure a planner should follow when a budget will not close — specifying when to use the ranking, when to use the list, and how to decide between them. Then apply it to a $6,000 deficit at 170 guests.
D.2. Critique the threshold concept. "Guest count is the master variable" is presented as arithmetic. Construct the case that it is a planner's convenience — that for many couples the guest list is the point of the wedding, that treating it as the primary variable optimizes for the planner's problem rather than the client's, and that a planner who leads with it is imposing a value judgment. Then respond. Where is the line between informing a choice and steering one?
D.3. The ethics of the B-list. The chapter defends tiering on the grounds that the ranking happens either way. Construct the strongest objection. Then consider: does your answer change for a guest who is on the B-list because of budget versus one who is there because the couple genuinely likes them less?
D.4. Transfer. Apply the fully-variable / step / fixed decomposition to a domain outside events: a restaurant adding covers, a conference adding attendees, an airline adding a passenger, a school adding a student. Where are the steps? What does each industry do about them that events could learn from?
D.5. Design the missing tool. A client wants to know, in real time, what any change to the guest list costs. Design the artifact — spreadsheet, one-pager, whatever — that gives them this without requiring them to call you. Specify what it shows, what it deliberately does not, and what could go wrong if a client uses it unsupervised.
Part M: Mixed Practice (Interleaved) ⭐⭐–⭐⭐⭐
M.1. (Ch.3 + Ch.5) Sam's mother emails you directly asking to add four names. She is a payer and not a decider. Write your reply.
M.2. (Ch.4) The couple ranked "guest comfort" first and are at 168 guests in a room that comfortably holds 140. Is this a contradiction? What do you say?
M.3. (Ch.1) A couple at a raw site adds 12 guests, crossing from 138 to 150. List everything that changes, including the things that are not on any per-head price list.
M.4. (Looks like one thing, is another) A client says: "We're fine on numbers, we're at 150 and the venue holds 180." What have they not understood, and what is the one question that reveals it?
M.5. (Ch.2 + Ch.5) You sold month-of coordination and arrive at week −8 to find 178 confirmed guests, a venue that seats 160, and no rain plan. Which of these is inside your scope, which is outside, and what do you actually do tonight?
Part E: Research and Extension ⭐⭐⭐⭐
E.1. Investigate attendance rates in a specific cultural or regional context different from the §5.6 table's implicit assumptions. Interview at least two people who have planned weddings in that context. What do the rates look like, and what structural features of the community explain the difference? (Chapter 21 will build on this.)
E.2. Examine the guaranteed-count mechanism across three real catering contracts. How is the guarantee defined, when is it due, what is the penalty for exceeding it, and what happens if fewer attend? Write 500 words on how much the mechanism varies and what you would negotiate.
E.3. Build the marginal cost curve empirically. For one real venue, plot total cost against guest count from 80 to 250 in increments of 2. Identify every discontinuity. Then compute the average marginal cost across the range and compare it to the naive per-head figure. How large is the error, and in which direction?
Solutions
Selected solutions: appendices/answers-to-selected.md.
Rubrics for open-ended items: instructor-guide/additional-assessments/all-assessments.md.