When San Francisco's streets were magically cleaned in 48 hours for President Xi's visit, it demonstrated that persistent urban problems like homelessness and open-air drug markets are not intractable. Rather, they are the result of a lack of political will, which can be overcome when necessary.

The public perceives a city's ability to manage trash collection as a proxy for its overall competence. Similar to "pothole politics" or snow removal, visible failures in this basic service lead citizens to logically leap to the conclusion that the government is failing in other, less visible ways.

Contrary to the economic theory that more choice is always better, people sometimes prefer fewer options. Removing a tempting choice, like a bowl of cashews before dinner, can lead to better outcomes by acting as a pre-commitment device, which helps overcome a lack of self-control.

Recycling is often the most difficult, polluting, and energy-intensive way to extend a product's life. The environmental hierarchy should be "Reduce, Reuse, Recycle," yet we default to recycling first. Refurbishing and repairing products is far more efficient, cheaper, and better for the planet.

San Francisco's process to select and roll out a new public trash can design will span nearly nine years. This lengthy timeline illustrates how mandated public feedback periods, competitive bidding laws, contracting, and unforeseen crises like COVID can extend the schedule for seemingly simple infrastructure projects far beyond public expectation.

The principles influencing shoppers are not limited to retail; they are universal behavioral nudges. These same tactics are applied in diverse fields like public health (default organ donation), finance (apps gamifying saving), and even urban planning (painting eyes on bins to reduce littering), proving their broad applicability to human behavior.

NYC spends more per homeless person than the median household income, yet its homeless population is growing. This suggests that without proper outcome tracking and incentive alignment, massive funding can simply make a social problem more comfortable and entrenched, rather than solving it.

San Francisco's Public Works department reveals a paradoxical challenge: for every citizen request to add a trash can, another request often follows to remove it from the same spot. This is because public cans can become magnets for illegal dumping and other nuisances, creating a constant tension between convenience and order.

San Francisco's $20,000 trash can prototypes drew media outrage, but this cost covered initial industrial design, development, and custom manufacturing. The final mass-produced cans cost a more reasonable $1,400 each, showing how prototype expenses don't reflect the final unit price for public infrastructure.