The Growing Localness of the Canadian City, or, On the Continued (Ir)relevance of Economic Base Theory

The past 50 years have brought massive changes in the patterns of economic activity around the world. Not only has global trade increased, but, precisely because of this, many scholars suggest that local (and regional) networks of production and exchange have become more prevalent and important. The nature of local economic development has, as a result, changed quite substantially. And yet theoretical approaches to it largely have not. Fifty years after Douglass North introduced economic base theory - asserting that economies grow only through increased exports - it remains the familiar refrain, if not the basis, of local economic development theory. We think it is about time to reassess the merits of base theory as an approach to, and explanation of, local economic development. Accordingly, in this article, we review briefly North's argument for base theory and the debate it stirred up early on. Then we present two evaluations of its current relevance. The first is theoretical: we consider whether changes in the patterns of economic activity in the global north, including the emergence of local/regional networks of production and exchange and the growth of consumer services, have made it possible to achieve economic growth without increasing exports. The second is empirical: using the minimum requirements method, we examine whether the economies of Canada's cities have become more locally oriented and, if so, whether they have grown. Both evaluations indicate that economic development is indeed possible through increased local activity (although exports remain important). We conclude that it is time to consider more nuanced models of local economic development that accommodate the multiple ways in which development can be achieved.

Existing and emerging cyanocidal compounds: new perspectives for cyanobacterial bloom mitigation

To help ban the use of general toxic algicides, research efforts are now directed towards the discovery of compounds that are specifically acting as cyanocides. Here, we review the past and look forward into the future, where the less desirable general algicides like copper sulphate, diuron or endothall may become replaced by compounds that show better specificity for cyanobacteria and are biodegradable or transform into non-toxic products after application. For a range of products, we review the activity, the mode of action, effectiveness, durability, toxicity towards non-target species, plus costs involved, and discuss the experience with and prospects for small water volume interventions up to the mitigation of entire lakes; we arrive at recommendations for a series of natural products and extracted organic compounds or derived synthetic homologues with promising cyanocidal properties, and briefly mention emerging nanoparticle applications. Finally, we detail on the recently introduced application of hydrogen peroxide for the selective killing of cyanobacteria in freshwater lakes