In this episode, why some economists are worried about a growing army of "zombie companies" with lots of debts – and what this could mean for the shape of our economies. And the researchers who've found a new way to prevent predators from eating the eggs of endangered birds – via a form of biological, psychological warfare. Welcome to episode 10 of The Conversation Weekly, the world explained by experts.

With interest rates at record lows, many companies have been able to borrow money at very little cost. This cheap cash, which was flooding financial markets before the pandemic began, led some companies to rack up big debts. Economists call these “zombie companies” – firms that may struggle to pay the interest on their large debts. It’s a problem that’s been exacerbated by the pandemic, as revenues dried up in many sectors of the economy. Karl Schmedders, professor of finance at the International Institute for Management Development in Lausanne, Switzerland, explains how zombie companies are born, why the pandemic could have made the problem worse and what might happen next. And Sandy Brian Hager, senior lecturer in international political economy at City, University of London, explains his research about why the size of a company has a bearing on the shape of the recovery ahead.

In our second story, we hear about a new technique to protect endangered birds whose nests are often attacked by invasive predators. Scientists used fake smells to trick predators such as ferrets and hedgehogs into ignoring the birds' eggs. Catherine Price, postdoctoral researcher in conservation biology at the University of Sydney, tells us what happened when they tested the idea in the Mackenzie Basin on New Zealand's South Island.

And Luthfi Dzulfikar, associate editor at The Conversation in Indonesia, gives us his recommended reads. 

The Conversation Weekly is produced by Mend Mariwany and Gemma Ware, with sound design by Eloise Stevens. Our theme music is by Neeta Sarl.

If you'd like to sign up for The Conversation's free daily newsletter, please subscribe here. To get in touch, find us on Twitter @TC_Audio or on Instagram at theconversationdotcom. Or you can email us on [email protected]. Full credits for this episode can be found here.

Further reading

• Takeovers: a tidal wave of buyouts is coming in 2021 – here’s what it means, by Karl Schmedders and Patrick Reinmoeller, International Institute for Management Development (IMD)
• Attack of zombie companies: don’t let them eat bailouts that are vital to restore the economy, by Robert Earle, University of Zürich; Jung Park and Karl Schmedders, International Institute for Management Development (IMD)
• Giant firms have a hidden borrowing advantage that has helped keep them on top for decades – new research, by Sandy Brian Hager, City, University of London and Joseph Baines, King's College London
• Biggest companies pay the least tax, leaving society more vulnerable to pandemic – new research, by Sandy Brian Hager, City, University of London and Joseph Baines, King's College London
• Scientists used ‘fake news’ to stop predators killing endangered birds — and the result was remarkable, by Peter Banks, University of Sydney and Catherine Price, University of Sydney
• A study on the undocumented shows the glaring inequality gap in Indonesia's civil registration system, by Widi Sari, Harriz Jati, Meutia Aulia Rahmi, and Santi Kusumaningrum, PUSKAPA (in Bahasa Indonesia)
• National Film Day: Indonesia's young "santri" are producing film to preserve and criticize the Islamic boarding school tradition, by Ahmad Nuril Huda, Universitas Islam Negeri Raden Intan Lampung (in Bahasa Indonesia)