Historians have demonstrated that the rise of Western Europe depended in large part on natural resources and labour forcibly appropriated from the global South during the colonial period, on a vast scale. Spain extracted gold and silver from the Andes, Portugal extracted sugar from Brazil, France extracted fossil fuels, minerals and agricultural products from West Africa, Belgium extracted rubber from the Congo; and Britain extracted cotton, opium, grain, timber, tea and countless other commodities from its colonies around the world – all of which entailed the exploitation of Southern labour on coercive terms, including through mass enslavement and indenture. This pattern of appropriation was central to Europe’s industrial growth, and to financing the expansion and industrialization of European settler colonies, including Canada, Australia, New Zealand and the United States, which went on to develop similarly imperialist orientations toward the South (e.g., Naoroji, 1902, Pomeranz, 2000, Beckert, 2015, Moore, 2015, Bhambra, 2017, Patnaik, 2018, Davis, 2002). According to the conventional public narrative, colonial patterns of extraction ended with the withdrawal of colonial troops, flags and bureaucrats from the territories of the global South. Today, we are told, the world economy functions as a meritocracy: countries that have strong institutions, good markets, and a steadfast work ethic become rich and successful, while countries that lack these things, or which are hobbled by corruption and bad governance, remain poor. This assumption underpins dominant perspectives in the field of international development (Sachs, 2005, Collier, 2007, Rostow, 1990, Moyo, 2010, Calderisi, 2007, Acemoglu and Robinson, 2012), and is reinforced by the rhetoric, common among neoclassical economists, that free-trade globalization has created an “even playing field”. This narrative of post-colonial innocence has long come under critique. In the 1960s and 1970s, economists and historians associated with dependency theory and world-system theory argued that the general structure of the colonial economy remains in place, with industrial growth in the global North continuing to rely on appropriation from the South well into the post-colonial era (Rodney, 1972, Prebisch, 1950, Galeano, 1973, Wallerstein, 1974, Frank, 1967, Nkrumah, 1965). Rich countries and monopolistic corporations leverage their geopolitical and commercial dominance in the world economy to depress or cheapen the prices of resources and labour in the global South, both at the level of whole national economies as well as within global commodity chains (section 5.2). As a result, for every unit of embodied resources and labour that the South imports from the North they have to export many more units to pay for it, enabling the North to achieve a net appropriation through trade. This dynamic was theorized by Emmanuel (1972) and Amin (1978) as a process of “unequal exchange”. Emmanuel and Amin argued that unequal exchange enables a “hidden transfer of value” from the global South to the global North, or from periphery to core, which takes place subtly and almost invisibly, without the overt coercion of the colonial apparatus and therefore without provoking moral outrage. Prices are naturalized on the grounds that they represent “utility”, or “value”, or the outcome of “market mechanisms” such as supply and demand, obscuring the extent to which they are determined by power imbalances in the global political economy. Price differentials in international trade therefore function as an effective method of maintaining the patterns of appropriation that once overtly defined the colonial economy, allowing blame for “underdevelopment” to be shifted onto the victims. This pattern remains entrenched despite the fact that, with the rise of neoliberal globalization in the 1980s, manufacturing has shifted overwhelmingly to the global South, to the point where Southern countries contribute the vast majority of the world’s industrial labour and industrial production (Smith, 2016). Northern appropriation from the South comprises resources and labour embodied not only in primary commodities but also in manufactured goods, including high-technology products such as smartphones, computer chips, cars, designer fashion, etc., along with intermediate parts. Most of this appropriation occurs through global commodity chains, wherein Northern firms deploy monopsony and monopoly power to depress Southern suppliers’ prices at every node, from extraction to manufacture, while setting final prices as high as possible (Suwandi, 2019, Clelland, 2014). Several attempts have been made to estimate the monetary value of appropriation or drain from the global South through unequal exchange, generally by correcting the South’s export revenues for North-South price distortions in order to arrive at some representation of “losses”. Amin (1978: 144) focused on international wage inequalities, although doing so meant he was unable to account for other inputs that may affect overall price differentials. Köhler (1998) developed a more holistic method, using the distortion factor between market exchange rates (MER) and purchasing power parity (PPP) as a proxy for overall price inequalities. Using a modified version of Köhler’s method, recent research has found that in 2015 drain from the South through unequal exchange amounted to $2.1 trillion (constant 2011 dollars), represented in Northern prices (Hickel et al., 2021). Köhler’s proxy approach is limited in several respects, however. It relies on PPP figures that do not adequately account for the comparatively high prices of Northern exports; it relies on GDP figures that are affected by the low prices of imports from the South; and it compares Southern exports to prices across whole economies, rather than to those of only traded goods. All of this leads to underestimating the scale of drain (see Hickel et al., 2021). Perhaps more importantly, existing methods are limited in that they rely on trade revenues and price differentials as proxies by which to estimate drain without any reference to actual goods, precisely because goods remain hidden behind monetary trade data. Moreover, the conventional monetary data relates only to traded goods themselves and does not capture the upstream inputs that go into producing them, the prices of which significantly affect trade prices and, in a context of globally dispersed commodity chains, may involve many different countries. For instance, if the USA exports an aircraft, it may embody parts imported from China and Bolivia, which existing methods can account for using conventional trade data (e.g., Hickel et al., 2021), but it also embodies the materials and labour deployed in China and Bolivia to produce those parts, which existing methods cannot capture. Here we take a novel approach that seeks to overcome the limitations of previous work. Following Dorninger et al. (2021), we use a “footprint” analysis of input–output data to quantify the physical scale of raw materials, land, energy and labour embodied in trade between the North and South, looking not only at traded goods themselves but also the upstream resources and labour that go into producing and transporting those goods, including the machines, factories, infrastructure, etc. (Lenzen et al., 2013, Lenzen et al., 2012, Wiedmann et al., 2015). This approach builds on scholarship in ecological economics and industrial ecology. Using footprint metrics allows us to capture inputs even when they flow through complex global commodity chains: we can identify where the labour and resources are rendered and where the value is ultimately captured. This enables us to ground our analysis of unequal exchange in real resources and a more robust assessment of prices and price inequalities in trade, while maximizing the comparability of flows between the North and South. Using environmental input–output data, we find that there has been a significant net flow of embodied labour and natural resources from the global South to the global North over the period 1990 to 2015 (section 3). By comparing the physical scale of net resource flows to global price differentials, we estimate the monetary dimension of the drain. This is calculated not with respect to some objectively “correct” price for labour and resources (there is no such thing), but rather by representing the drain in terms of prevailing Northern prices, as well as in terms of global average prices for comparison. For “prices” we use trade in value-added (TiVA) per unit of resources embodied in traded goods, which is the monetary counterpart of our footprint method. Grounding our analysis in the physical dimensions of unequal exchange is important for several reasons. First, these resources – raw materials, land, labour and energy – embody the productive potential that is required for meeting human needs (use-value) and for generating economic growth (exchange-value). Physical drain is therefore ultimately what drives global inequalities in terms of access to provisions, as well as in terms of GDP or income (see Hornborg, 2020). Second, this approach allows us to maintain sight of the ecological impacts of unequal exchange. We know that excess energy and material consumption in high-income nations, facilitated by appropriation from the rest of the world, is causing ecological breakdown on a global scale. Tracing flows of resources embodied in trade allows us to determine the extent to which Northern appropriation is responsible for ecological impacts in the South; i.e., ecological debt (Roberts and Parks, 2009, Warlenius et al., 2015, Hornborg and Martinez-Alier, 2016).