Table 1 Summary of five nudge scenarios, variations, and design element varied across variations

1. Eat Less Butter

Patrons must actively ask a waiter for butter.

Butter is reachable for patrons at the buffet, but it is made to be difficult to reach.

Shift in nudge intrusiveness by decreasing the ‘social’ cost of opting out.

2. Eat Less Meat

A vegetarian menu is placed on the table. A normal menu with meat options is available but must be actively fetched at the counter.

A menu with both meat and vegetarian meal options is placed at the table; however, vegetarian dishes are placed on the first page of the menu.

Shift in nudge intrusiveness by decreasing the ‘physical’ cost of opting out.

3. Climate-Friendly Groceries

Consumers are automatically provided a pre-filled cart and must click products individually to remove them if they are not desired.

Consumers are presented with a choice about receiving a pre-filled cart, which can be emptied with a single click.

Increased nudge transparency.

4. Low-Energy Side Dishes

Low energy dense side dishes are bolded on the menu.

All side dishes have the same font weight, but calorie information is provided by each side dish on the menu.

Shift from a salience nudge to an information nudge.

5. Donations for Regional Dairy Products

A 10-cent donation sticker is placed on regional milk products, to which customers must actively object at checkout.

The cashier asks the customer if they agree to a donation on regional milk products in their cart at checkout.

Shift in nudge intrusiveness from a default structure to a forced active choice.