This conference has been going on for remarkable 20 years. Of these, I've attended four, first as a researcher and now as an editor. Every time I got a lot out of it (and I admit that I'm the skeptical sort of conference attendant): interesting new findings, compelling discussions and, most importantly, great energy to go back to the office and keep doing my job. This energy comes from a fresh reminder of why we're doing this (editing on sustainability matters) and what a great bunch of scholars work on it. 

For those who see economics researchers from outside (like I did as an undergrad), these researchers seem to be a boring species with a dull collar shirt and a briefcase, who love their equations and being harsh to each other. Not really; they're rich and diverse, and so are the paradigms with which they work. Related to sustainability, name Environmental *, Ecological *, Natural resource *, Development *, Behavioural *, Institutional *... Economists, and each of these subspecies will present clearly distinctive features. Despite notable disagreements, many of them share a common concern for the planet, or a sort of pro-social concern —echoing the workshop that took place as a warm-up for the conference.

A lot of what they don't agree on, is the specifics of how this concern should be addressed: the methods, the precise normative goals, the policy instruments (taxes, regulation, voluntary measures...). These are so varied that it's hard to pinpoint any on which all Econ. sp would concur. That's partially what makes great food for thought when one dives into these debates (and perhaps also what makes them feel harsh). Indeed Professor Ferraro, who's triggered a tide in environmental policy impact evaluation studies, made us think at the conference whether research on human preferences, typically focused on behaviour and goals, should also heed preferences about the policy instruments themselves. For example, in which way would you be most persuaded to avoid single-use coffee cups? If: (a) someone paid you to stop using them, (b) it was forbidden, (c) you had to pay extra to get one every day, (d) your fellows showed off their reusable cup, or (e) [insert your policy instrument idea here].

This year at BIOECON, following an increasing trend but marking what I'd call a milestone, these Econ. species were joined by illustrious representatives of others. Professor Williams told us the many different geological markers scientists are considering in order to establish the Anthropocene as a new geological era. Professor Sutherland told us about the challenges of assessing diverse and sometimes incommensurable evidence in evidence-based conservation, something on which he co-authored a series of principles just published at Nature Sustainability. And so on.

Two practical things make this conference so full of good energy (despite that research on the environment is oftentimes saddening). The size and venue encourage interaction: not too many people, good balance between senior and early-career researchers and a calm environment that invites to think and discuss. Also, presenters submit their full paper draft months in advance, which means that they come to present actual results or work that is well advanced (this doesn't always happen in disciplines around social-environmental studies). Of course, in addition to this, there were lots of exchanges in the hallways, lots of ideas for cool and potentially useful papers, and conversations over dinner spanning beyond the field and stemming from the pro-social concern that characterises this crowd: from austerity politics to how outdoor activities help risk management.

The XX Annual BIOECON conference (http://www.bioecon-network.org/), was held at Kings College Cambridge, organised by the Department of Land Economy, University of Cambridge and the Department of Geography and Environment, LSE.