We live in the plastic age (the "plasticene"), producing over 300 million tonnes (mt) of plastic every year globally, 5–15 mt of which flow into already polluted oceans. Plastic remains a key material in the global economy, but low rates of collection, reuse and recycling, emissions of...

We use natural experiments plausibly exogenous, anticipated increases in the piece rate to study how effort responds to incentives. Our first finding, like some previous studies, lends little support to the view that incentives increase effort: raising the piece rate has zero effect on total...