Dr Ian MacKenzie
Research Program Leader - Applied Economics
Australian Institute for Business and Economics
+61 7 336 56619
Room 615, Level 6, Colin Clark Building (#39)
Publications
Book Chapter
Hintermann, Beat and MacKenzie, Ian A. (2011). Reassessing the importance of initial allocation methods in emission permit markets. Advances in environmental research. (pp. 207-238) edited by Justin A. Daniels. New York: Nova Publishing.
Journal Articles
Khezr, Peyman and MacKenzie, Ian A. (2021). An allocatively efficient auction for pollution permits. Environmental and Resource Economics, 78 (4), 571-585. doi: 10.1007/s10640-021-00543-3
Khezr, Peyman and MacKenzie, Ian A. (2021). Revenue and efficiency in pollution permit allocation mechanisms. Energy Economics, 93 105033, 105033. doi: 10.1016/j.eneco.2020.105033
Taylor, Jonathon, Shrubsole, Clive, Symonds, Phil, Mackenzie, Ian and Davies, Mike (2019). Application of an indoor air pollution metamodel to a spatially-distributed housing stock. Science of the Total Environment, 667, 390-399. doi: 10.1016/j.scitotenv.2019.02.341
Khezr, Peyman and MacKenzie, Ian A. (2018). Permit market auctions with allowance reserves. International Journal of Industrial Organization, 61, 283-306. doi: 10.1016/j.ijindorg.2018.09.005
Fiore, Arlene M., Fischer, Emily V., Milly, George P., Pandey Deolal, Shubha, Wild, Oliver, Jaffe, Daniel A., Staehelin, Johannes, Clifton, Olivia E., Bergmann, Dan, Collins, William, Dentener, Frank, Doherty, Ruth M., Duncan, Bryan N., Fischer, Bernd, Gilge, Stefan, Hess, Peter G., Horowitz, Larry W., Lupu, Alexandru, MacKenzie, Ian A., Park, Rokjin, Ries, Ludwig, Sanderson, Michael G., Schultz, Martin G., Shindell, Drew T., Steinbacher, Martin, Stevenson, David S., Szopa, Sophie, Zellweger, Christoph and Zeng, Guang (2018). Peroxy acetyl nitrate (PAN) measurements at northern midlatitude mountain sites in April: a constraint on continental source-receptor relationships. Atmospheric Chemistry and Physics, 18 (20), 15345-15361. doi: 10.5194/acp-18-15345-2018
Dickson, Alex, MacKenzie, Ian A. and Sekeris, Petros G. (2018). Rent-seeking incentives in share contests. Journal of Public Economics, 166, 53-62. doi: 10.1016/j.jpubeco.2018.08.004
Hood, Christina, MacKenzie, Ian, Stocker, Jenny, Johnson, Kate, Carruthers, David, Vieno, Massimo and Doherty, Ruth (2018). Air quality simulations for London using a coupled regional-to-local modelling system. Atmospheric Chemistry and Physics, 18 (15), 11221-11245. doi: 10.5194/acp-18-11221-2018
Ots, Riinu, Heal, Mathew R., Young, Dominique E., Williams, Leah R., Allan, James D., Nemitz, Eiko, Di Marco, Chiara, Detournay, Anais, Xu, Lu, Ng, Nga L., Coe, Hugh, Herndon, Scott C., Mackenzie, Ian A., Green, David C., Kuenen, Jeroen J.P., Reis, Stefan and Vieno, Massimo (2018). Modelling carbonaceous aerosol from residential solid fuel burning with different assumptions for emissions. Atmospheric Chemistry and Physics, 18 (7), 4497-4518. doi: 10.5194/acp-18-4497-2018
Finney, Declan L., Doherty, Ruth M., Wild, Oliver, Stevenson, David S., MacKenzie, Ian A. and Blyth, Alan M. (2018). A projected decrease in lightning under climate change. Nature Climate Change, 8 (3), 210-213. doi: 10.1038/s41558-018-0072-6
Khezr, Peyman and MacKenzie, Ian A. (2018). Consignment auctions. Journal of Environmental Economics and Management, 87, 42-51. doi: 10.1016/j.jeem.2017.11.003
Dickson, Alex and MacKenzie, Ian A. (2018). Strategic trade in pollution permits. Journal of Environmental Economics and Management, 87, 94-113. doi: 10.1016/j.jeem.2017.04.009
Doherty, Ruth M., Orbe, Clara, Zeng, Guang, Plummer, David A., Prather, Michael J., Wild, Oliver, Lin, Meiyun, Shindell, Drew T. and MacKenzie, Ian A. (2017). Multi-model impacts of climate change on pollution transport from global emission source regions. Atmospheric Chemistry and Physics, 17 (23), 14219-14237. doi: 10.5194/acp-17-14219-2017
Milojevic, Ai, Niedzwiedz, Claire L., Pearce, Jamie, Milner, James, MacKenzie, Ian A., Doherty, Ruth M. and Wilkinson, Paul (2017). Socioeconomic and urban-rural differentials in exposure to air pollution and mortality burden in England. Environmental Health: A Global Access Science Source, 16 (1) 104. doi: 10.1186/s12940-017-0314-5
Chalabi, Zaid, Milojevic, Ai, Doherty, Ruth M., Stevenson, David S., MacKenzie, Ian A., Milner, James, Vieno, Massimo, Williams, Martin and Wilkinson, Paul (2017). Applying air pollution modelling within a multi-criteria decision analysis framework to evaluate UK air quality policies. Atmospheric Environment, 167, 466-475. doi: 10.1016/j.atmosenv.2017.08.057
Silva, Raquel A., West, J. Jason, Lamarque, Jean-François, Shindell, Drew T., Collins, William J., Faluvegi, Greg, Folberth, Gerd A., Horowitz, Larry W., Nagashima, Tatsuya, Naik, Vaishali, Rumbold, Steven T., Sudo, Kengo, Takemura, Toshihiko, Bergmann, Daniel, Cameron-Smith, Philip, Doherty, Ruth M., Josse, Beatrice, MacKenzie, Ian A., Stevenson, David S. and Zeng, Guang (2017). Future global mortality from changes in air pollution attributable to climate change. Nature Climate Change, 7 (9), 647-651. doi: 10.1038/nclimate3354
Lin, Chun, Heal, Mathew R., Vieno, Massimo, MacKenzie, Ian A., Armstrong, Ben G., Butland, Barbara K., Milojevic, Ai, Chalabi, Zaid, Atkinson, Richard W., Stevenson, David S., Doherty, Ruth M. and Wilkinson, Paul (2017). Spatiotemporal evaluation of EMEP4UK-WRF v4.3 atmospheric chemistry transport simulations of health-related metrics for NO2, O3, PM10, and PM2.5 for 2001-2010. Geoscientific Model Development, 10 (4), 1767-1787. doi: 10.5194/gmd-10-1767-2017
MacKenzie, Ian (2017). Rent creation and rent seeking in environmental policy. Public Choice, 171 (1-2), 145-166. doi: 10.1007/s11127-017-0401-8
MacKenzie, Ian A. (2016). Review of Political Economy and Instruments of Environmental Politics, by Friedrich Schneider, Andrea Kollman and Johannes Reichl (MIT Press, Cambridge, MA, 2015), pp. 285. Economic Record, 92 (299), 670-671. doi: 10.1111/1475-4932.12300
Ots, Riinu, Vieno, Massimo, Allan, James D., Reis, Stefan, Nemitz, Eiko, Young, Dominique E., Coe, Hugh, Di Marco, Chiara, Detournay, Anais, Mackenzie, Ian A., Green, David C. and Heal, Mathew R. (2016). Model simulations of cooking organic aerosol (COA) over the UK using estimates of emissions based on measurements at two sites in London. Atmospheric Chemistry and Physics, 16 (21), 13773-13789. doi: 10.5194/acp-16-13773-2016
Silva, Raquel A., West, J. Jason, Lamarque, Jean-François, Shindell, Drew T., Collins, William J., Dalsoren, Stig, Faluvegi, Greg, Folberth, Gerd, Horowitz, Larry W., Nagashima, Tatsuya, Naik, Vaishali, Rumbold, Steven T., Sudo, Kengo, Takemura, Toshihiko, Bergmann, Daniel, Cameron-Smith, Philip, Cionni, Irene, Doherty, Ruth M., Eyring, Veronika, Josse, Beatrice, MacKenzie, Ian A., Plummer, David, Righi, Mattia, Stevenson, David S., Strode, Sarah, Szopa, Sophie and Zengast, Guang (2016). The effect of future ambient air pollution on human premature mortality to 2100 using output from the ACCMIP model ensemble. Atmospheric Chemistry and Physics, 16 (15), 9847-9862. doi: 10.5194/acp-16-9847-2016
Ots, Riinu, Young, Dominique E., Vieno, Massimo, Xu, Lu, Dunmore, Rachel E., Allan, James D., Coe, Hugh, Williams, Leah R., Herndon, Scott C., Ng, Nga L., Hamilton, Jacqueline F., Bergström, Robert, Di Marco, Chiara, Nemitz, Eiko, Mackenzie, Ian A., Kuenen, Jeroen J. P., Green, David C., Reis, Stefan and Heal, Mathew R. (2016). Simulating secondary organic aerosol from missing diesel-related intermediate-volatility organic compound emissions during the Clean Air for London (ClearfLo) campaign. Atmospheric Chemistry and Physics, 16 (10), 6453-6473. doi: 10.5194/acp-16-6453-2016
Ots, R., Young, D. E., Vieno, M., Xu, L., Dunmore, R. E., Allan, J. D., Coe, H., Williams, L. R., Herndon, S. C., Ng, N. L., Hamilton, J. F., Bergström, R., Di Marco, C., Nemitz, E., Mackenzie, I. A., Kuenen, J. J.P., Green, D. C., Reis, S. and Heal, M. R. (2016). Simulating secondary organic aerosol from missing diesel-related intermediate-volatility organic compound emissions during the Clean Air for London (ClearfLo) campaign. Atmospheric Chemistry and Physics Discussions, 2016. doi: 10.5194/acp-2015-920
MacKenzie, Ian A. and Ohndorf, Markus (2016). Caps on Coasean Transfers. Oxford Economic Papers, 68 (2) gpv091, 566-584. doi: 10.1093/oep/gpv091
MacKenzie, Ian A. and Ohndorf, Markus (2016). Coasean bargaining in the presence of Pigouvian taxation. Journal of Environmental Economics and Management, 75, 1-11. doi: 10.1016/j.jeem.2015.09.003
Malkin, Tamsin L., Heard, Dwayne E., Hood, Christina, Stocker, Jenny, Carruthers, David, Mackenzie, Ian A., Doherty, Ruth M., Vieno, Massimo, Lee, James, Kleffmann, Jörg, Laufs, Sebastian and Whalley, Lisa K. (2016). Assessing chemistry schemes and constraints in air quality models used to predict ozone in London against the detailed Master Chemical Mechanism. Faraday Discussions, 189, 589-616. doi: 10.1039/c5fd00218d
Gerigk, Joschka, MacKenzie, Ian A. and Ohndorf, Markus (2015). A model of benchmarking regulation: revisiting the efficiency of environmental standards. Environmental and Resource Economics, 62 (1), 59-82. doi: 10.1007/s10640-014-9815-7
Brunnschweiler, Christa N., Jennings, Colin and MacKenzie, Ian (2014). A study of expressive choice and strikes. European Journal of Political Economy, 2014, 111-125. doi: 10.1016/j.ejpoleco.2014.01.004
Naik, V., Voulgarakis, A., Fiore, A. M., Horowitz, L. W., Lamarque, J. F., Lin, M., Prather, M. J., Young, P. J., Bergmann, D., Cameron-Smith, P. J., Cionni, I., Collins, W. J., Dalsøren, S. B., Doherty, R., Eyring, V., Faluvegi, G., Folberth, G. A., Josse, B., Lee, Y. H., MacKenzie, I. A., Nagashima, T., Van Noije, T. P.C., Plummer, D. A., Righi, M., Rumbold, S. T., Skeie, R., Shindell, D. T., Stevenson, D. S., Strode, S. ... Zeng, G. (2013). Preindustrial to present-day changes in tropospheric hydroxyl radical and methane lifetime from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). Atmospheric Chemistry and Physics, 13 (10), 5277-5298. doi: 10.5194/acp-13-5277-2013
Lamarque, J. F., Dentener, F., McConnell, J., Ro, C. U., Shaw, M., Vet, R., Bergmann, D., Cameron-Smith, P., Dalsoren, S., Doherty, R., Faluvegi, G., Ghan, S. J., Josse, B., Lee, Y. H., Mackenzie, I. A., Plummer, D., Shindell, D. T., Skeie, R. B., Stevenson, D. S., Strode, S., Zeng, G., Curran, M., Dahl-Jensen, D., Das, S., Fritzsche, D. and Nolan, M. (2013). Multi-model mean nitrogen and sulfur deposition from the atmospheric chemistry and climate model intercomparison project (ACCMIP): Evaluation of historical and projected future changes. Atmospheric Chemistry and Physics, 13 (16), 7997-8018. doi: 10.5194/acp-13-7997-2013
Bowman, K. W., Shindell, D. T., Worden, H. M., Lamarque, J. F., Young, P. J., Stevenson, D. S., Qu, Z., De La Torre, M., Bergmann, D., Cameron-Smith, P. J., Collins, W. J., Doherty, R., Dalsøren, S. B., Faluvegi, G., Folberth, G., Horowitz, L. W., Josse, B. M., Lee, Y. H., MacKenzie, I. A., Myhre, G., Nagashima, T., Naik, V., Plummer, D. A., Rumbold, S. T., Skeie, R. B., Strode, S. A., Sudo, K., Szopa, S., Voulgarakis, A. ... Worden, J. R. (2013). Evaluation of ACCMIP outgoing longwave radiation from tropospheric ozone using TES satellite observations. Atmospheric Chemistry and Physics, 13 (8), 4057-4072. doi: 10.5194/acp-13-4057-2013
Stevenson, D. S., Young, P. J., Naik, V., Lamarque, J. F., Shindell, D. T., Voulgarakis, A., Skeie, R. B., Dalsoren, S. B., Myhre, G., Berntsen, T. K., Folberth, G. A., Rumbold, S. T., Collins, W. J., MacKenzie, I. A., Doherty, R. M., Zeng, G., Van Noije, T. P.C., Strunk, A., Bergmann, D., Cameron-Smith, P., Plummer, D. A., Strode, S. A., Horowitz, L., Lee, Y. H., Szopa, S., Sudo, K., Nagashima, T., Josse, B., Cionni, I. ... Archibald, A. (2013). Tropospheric ozone changes, radiative forcing and attribution to emissions in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). Atmospheric Chemistry and Physics, 13 (6), 3063-3085. doi: 10.5194/acp-13-3063-2013
Voulgarakis, A., Naik, V., Lamarque, J. F., Shindell, D. T., Young, P. J., Prather, M. J., Wild, O., Field, R. D., Bergmann, D., Cameron-Smith, P., Cionni, I., Collins, W. J., Dalsøren, S. B., Doherty, R. M., Eyring, V., Faluvegi, G., Folberth, G. A., Horowitz, L. W., Josse, B., MacKenzie, I. A., Nagashima, T., Plummer, D. A., Righi, M., Rumbold, S. T., Stevenson, D. S., Strode, S. A., Sudo, K., Szopa, S. and Zeng, G. (2013). Analysis of present day and future OH and methane lifetime in the ACCMIP simulations. Atmospheric Chemistry and Physics, 13 (5), 2563-2587. doi: 10.5194/acp-13-2563-2013
Lamarque, J. F., Shindell, D. T., Josse, B., Young, P. J., Cionni, I., Eyring, V., Bergmann, D., Cameron-Smith, P., Collins, W. J., Doherty, R., Dalsoren, S., Faluvegi, G., Folberth, G., Ghan, S. J., Horowitz, L. W., Lee, Y. H., MacKenzie, I. A., Nagashima, T., Naik, V., Plummer, D., Righi, M., Rumbold, S. T., Schulz, M., Skeie, R. B., Stevenson, D. S., Strode, S., Sudo, K., Szopa, S., Voulgarakis, A. and Zeng, G. (2013). The atmospheric chemistry and climate model intercomparison Project (ACCMIP): Overview and description of models, simulations and climate diagnostics. Geoscientific Model Development, 6 (1), 179-206. doi: 10.5194/gmd-6-179-2013
MacKenzie, Ian A. and Ohndorf, Markus (2013). Restricted Coasean bargaining. Journal of Public Economics, 97 (1), 296-307. doi: 10.1016/j.jpubeco.2012.11.002
Wild, O., Fiore, A. M., Shindell, D. T., Doherty, R. M., Collins, W. J., Dentener, F. J., Schultz, M. G., Gong, S., Mackenzie, I. A., Zeng, G., Hess, P., Duncan, B. N., Bergmann, D. J., Szopa, S., Jonson, J. E., Keating, T. J. and Zuber, A. (2012). Modelling future changes in surface ozone: A parameterized approach. Atmospheric Chemistry and Physics, 12 (4), 2037-2054. doi: 10.5194/acp-12-2037-2012
MacKenzie, Ian A., Ohndorf, Markus and Palmer, Charles (2012). Enforcement-proof contracts with moral hazard and precaution: ensuring 'permanence' in carbon sequestration. Oxford Economic Papers, 64 (2) gpr057, 350-374. doi: 10.1093/oep/gpr057
MacKenzie, Ian A. and Ohndorf, M. (2012). Optimal monitoring for project-based emissions trading systems under asymmetric information. Journal of Regulatory Economics, 42 (2), 180-203. doi: 10.1007/s11149-012-9196-1
Fell, Harrison, MacKenzie, Ian A. and Pizer, William A. (2012). Prices versus quantities versus bankable quantities. Resource and Energy Economics, 34 (4), 607-623. doi: 10.1016/j.reseneeco.2012.05.004
MacKenzie, Ian A. and Ohndorf, Markus (2012). Cap-and-trade, taxes, and distributional conflict. Journal of Environmental Economics and Management, 63 (1), 51-65. doi: 10.1016/j.jeem.2011.05.002
MacKenzie, Ian A. (2011). Tradable permit allocations and sequential choice. Resource and Energy Economics, 33 (1), 268-278. doi: 10.1016/j.reseneeco.2010.06.004
Hanley, Nick and MacKenzie, Ian A. (2010). The effects of rent seeking over tradable pollution permits. BE Journal of Economic Analysis and Policy, 10 (1) 56, 56.1-56.26. doi: 10.2202/1935-1682.2497
Manney, G. L., Harwood, R. S., MacKenzie, I. A., Minschwaner, K., Allen, D. R., Santee, M. L., Walker, K. A., Hegglin, M. I., Lambert, A., Pumphrey, H. C., Bernath, P. F., Boone, C. D., Schwartz, M. J., Livesey, N. J., Daffer, W. H. and Fuller, R. A. (2009). Satellite observations and modeling of transport in the upper troposphere through the lower mesosphere during the 2006 major stratospheric sudden warming. Atmospheric Chemistry and Physics, 9 (14), 4775-4795. doi: 10.5194/acp-9-4775-2009
MacKenzie, Ian A., Hanley, Nick and Kornienko, Tatiana (2009). Using contests to allocate pollution permits. Energy Policy, 37 (7), 2798-2806. doi: 10.1016/j.enpol.2009.03.030
Fiore, A. M., Dentener, F. J., Wild, O., Cuvelier, C., Schultz, M. G., Hess, P., Textor, C., Schulz, M., Doherty, R. M., Horowitz, L. W., MacKenzie, I. A., Sanderson, M. G., Shindell, D. T., Stevenson, D. S., Szopa, S., Van Dingenen, R., Zeng, G., Atherton, C., Bergmann, D., Bey, I., Carmichael, G., Collins, W. J., Duncan, B. N., Faluvegi, G., Folberth, G., Gauss, M., Gong, S., Hauglustaine, D., Holloway, T. ... Zuber, A. (2009). Multimodel estimates of intercontinental source-receptor relationships for ozone pollution. Journal of Geophysical Research Atmospheres, 114 (4) D04301. doi: 10.1029/2008JD010816
Sanderson, Michael G., Dentener, F. J., Fiore, A. M., Cuvelier, C., Keating, T. J., Zuber, A., Atherton, C. S., Bergmann, D. J., Diehl, T., Doherty, R. M., Duncan, B. N., Hess, P., Horowitz, L. W., Jacob, D. J., Jonson, J. E., Kaminski, J. W., Lupu, A., MacKenzie, I. A., Mancini, E., Marmer, E., Park, R., Pitari, G., Prather, M. J., Pringle, K. J., Schroeder, S., Schultz, M. G., Shindell, D. T., Szopa, S., Wild, O. and Wind, P. (2008). A multi-model study of the hemispheric transport and deposition of oxidised nitrogen. Geophysical Research Letters, 35 (17) L17815. doi: 10.1029/2008GL035389
Shindell, D. T., Chin, M., Dentener, F., Doherty, R. M., Faluvegi, G., Fiore, A. M., Hess, P., Koch, D. M., MacKenzie, I. A., Sanderson, M. G., Schultz, M. G., Schulz, M., Stevenson, D. S., Teich, H., Textor, C., Wild, O., Bergmann, D. J., Bey, I., Bian, H., Cuvelier, C., Duncan, B. N., Folberth, G., Horowitz, L. W., Jonson, J., Kaminski, J. W., Marmer, E., Park, R., Pringle, K. J., Schroeder, S. ... Zuber, A. (2008). A multi-model assessment of pollution transport to the Arctic. Atmospheric Chemistry and Physics, 8 (17), 5353-5372. doi: 10.5194/acp-8-5353-2008
MacKenzie, Ian A., Hanley, Nick and Kornienko, Tatiana (2008). The optimal initial allocation of pollution permits: a relative performance approach. Environmental and Resource Economics, 39 (3), 265-282. doi: 10.1007/s10640-007-9125-4
Research Report
Wade, Belinda, MacKenzie, Ian, Agnew, Scott and Meath, Cristyn (2018). Australia’s evolving energy future: preparing business through systems modelling, organisational capabilities and stable energy policy. AIBE Industry Research Series Brisbane, QLD, Australia: The University of Queensland.
Working Papers
Friesen, Lana , Gangadharan, Lata , Khezr, Peyman and MacKenzie, Ian A. (2020). Mind your Ps and Qs! An Experiment on Variable Allowance Supply in the US Regional Greenhouse Gas Initiative. School of Economics Discussion Paper. 618. School of Economics, The University of Queensland, QLD Australia.
Khezr, Peyman and MacKenzie, Ian A. (2018). Revenue and efficiency in pollution permit allocation mechanisms. School of Economics.
Khezr, Peyman and MacKenzie, Ian A. (2018). An efficient and implementable auction for environmental rights. Discussion Paper. 587. School of Economics, University of Queensland.
Dickson, Alex, MacKenzie, Ian A. and Sekeris, Petros (2016). Sharing contests with general preferences. Discussion Paper Series. 573. School of Economics, University of Queensland.
Dickson, A. and MacKenzie, I. A. (2016). Strategic trade in pollution permits. Discussion Paper Series. 554. School of Economics, University of Queensland.
Khezr, Peyman and MacKenzie, Ian A. (2016). Permit market auctions with allowance reserves. Discussion Paper Series. 553. School of Economics, University of Queensland.
Khezr, Peyman and MacKenzie, Ian A. (2016). Consignment auctions. Discussion paper series. 558. School of Economics, University of Queensland.
MacKenzie, I.A. (2015). Prices versus quantities with distributional rent seeking. Discussion Paper Series. 548. School of Economics, University of Queensland.
MacKenzie, Ian (2014). Precaution with endogenous litigation choices. Discussion Papers, Department of Economics, University of Queensland. 535. School of Economics, University of Queensland.
Gerigk, Joschka, MacKenzie, Ian A. and Ohndorf, Markus (2014). A model of benchmarking regulation: revisiting the efficiency of environmental standards. 519. School of Economics, University of Queensland.
MacKenzie, Ian A. and Ohndorf, Markus (2014). Coasean Bargaining in the Presence of Pigouvian Taxation: Revisiting the Buchanan-Stubblebine-Turvey Theorem. School of Economics Discussion Paper Series. 515. School of Economics, University of Queensland.
MacKenzie, Ian A. and Ohndorf, Markus (2013). Caps on Coasean Transfers. 485. School of Economics, University of Queensland.
Newspaper Articles
MacKenzie, Ian A. (2018, 04 19). The recycling crisis in Australia: easy solutions to a hard problem The Conversation
MacKenzie, I. A. (2018, 02 26). Australia’s Emissions Reduction Fund is almost empty. It shouldn’t be refilled The Conversation
MacKenzie, I. A. (2017, 03 28). Plastic fantastic: how lotteries could revolutionise recycling The Conversation