L'égalité économique, un facteur indispensable pour préserver la biodiversité
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Equality and Plant Conservation by Countries
Equality and Plant Conservation by Countries
Demographic pressure, a product of inequality

Research has shown a strong empirical link between economic inequality and biodiversity loss. Gender equality helps stabilize human population growth and mitigate the pressure on other species and on natural resources. A minimum level of equality also appears necessary to successfully manage renewable natural resources for the benefit of all.

Economic equality, a worthy political goal in its own right, also greatly benefits the individual health of, and social harmony among, human beings (Wilkinson and Pickett, 2009). Might equality also promote environmental quality? Theorists and empiricists have debated this question for several decades now (for example, Olson, 1965; Boyce, 1994; Baland et al., 2007). In 2007, Mikkelson et al. reported a strong empirical link between economic inequality and biodiversity loss - in other words, a strongly positive relationship between equality and biodiversity (Mikkelson et al., 2007). They found such a relationship at two different scales: across countries throughout the world, and states throughout the US.

This chapter builds upon Mikkelson et al. (2007) in several ways. First, we examine subsequent analyses of equality-biodiversity links among different countries. We do not know of any further published studies of such links among different states or provinces within any country. One of the subsequent between-country analyses affirms a positive connection between equality and biodiversity (Holland et al., 2009), while the other denies such a connection (Pandit and Laband, 2009). This chapter thus first aims to explain this contrast. Second, we speculate about pathways through which equality may benefit biodiversity. These potential mechanisms partially overlap with linkages between biodiversity and poverty (Roe, 2010; Roe and Walpole, 2011; Billé et al., 2012), on one hand, and biodiversity and wealth or over-consumption (Sukhdev, 2010; Mikkelson, in review), on the other. Their identification could have a marked effect on public policy.

Third, we make a few suggestions about how to get economic equality onto the biodiversity protection agenda. Fourth and finally, we offer some thoughts about how best to achieve equality. While progressive taxation leaps first to many people's minds, deeper political and economic changes seem needed to ensure equality in the long term. We focus here on worker cooperatives - a far more egalitarian, and surprisingly competitive, form of business organization relative to typical corporations. A crucial defining feature of cooperatives - whether worker, consumer, or community co-ops - is that they operate democratically, i.e., one person, one vote (UN, 2012). In contrast, typical corporations (which we henceforth call "corporations" for short) not only subordinate workers to both managers and shareholders (Glasbeek, 2002), but also place ultimate control in the hands of the shareholders on a plutocratic basis - one dollar, one vote. Shifting the economy from corporations to co-ops will require changes in law and policy at all levels of government - local, regional, national and international (Schweickart, 2011). 

Recent controversy and future research: A case of non-monotonic improvement in data quality

As mentioned above, Mikkelson et al. (2007) found an equality-biodiversity link both among countries and among US states. But country-level data, in particular - on both economic equality and biological diversity - tend to be incomplete and inconsistent. Mikkelson et al., as well as Holland et al. (2009), and Pandit and Laband (2009), all drew upon the best data available at the time, produced by the Pitt Inequality Project (PIP) and the International Union for the Conservation of Nature (IUCN). However, they used very different versions of the PIP data.

The PIP corrected for several kinds of inconsistency between assessments of income inequality in different countries (Babones and Alvarez-Rivadulla, 2007). After performing these corrections, the PIP made three different data sets available. Mikkelson et al. used one of these, the Standardized Income Distribution Database, Version 1.0 (SIDD-1; see Reference # 17 in Mikkelson et al.). The SIDD-1 included corrected values for only those country-year combinations in which inequality had actually been measured. Holland et al. also made clear that they used only those measured country-year combinations (see p. 4), though they did not specify whether they drew from the original SIDD-1 or its revision, the SIDD-2. Pandit and Laband, in contrast, used the SIDD-3 (see p. 3222), which extrapolated and/or interpolated each country's inequality figures to yield estimates for every year from 1955 to 2005.

These extrapolations and interpolations inflated the data set by nearly six-fold, from the 1,218 country-year combinations in the SIDD-1 and SIDD-2 to 7,242 such combinations in the SIDD-3 (142 countries x 51 years). For some countries, the extrapolation was so extreme as to render the estimates for most years quite unbelievable. For example, for Barbados - one of the countries included in Pandit and Laband's analysis (see p. 3225) - the SIDD-3 lists precisely the same Gini index of inequality (0.5326) for all 51 years. The Gini index theoretically ranges from 0 - perfect equality - to 1, the case where one person takes all the income in a country. The fact that in the SIDD-3 Barbados has the same value for all years indicates that it contains only one corrected Gini index for that country, extrapolated all the way back to 1955 and forward to 2005. This spurious invariance contrasts markedly with the variation over time shown by the measured-then-corrected Gini indices in the SIDD-1 and SIDD-2. In the extreme case, Armenia's inequality rose by more than 0.35 after the fall of the Soviet Union.

Pandit and Laband did not mention the inclusion of such indefensibly long extrapolations as Barbados'. Instead, they touted the fact that they could include 87 countries in their analysis rather than just 45 as Mikkelson et al. had done. Controlling for the same set of other variables as Mikkelson et al. had, Pandit and Laband failed to detect any statistically significant relationship between equality and biodiversity. We conjecture, however, that this failure results from the likely fact that the vast majority of data points in the SIDD-3 used by Pandit and Laband are extrapolations or interpolations, rather than measured-then-corrected Gini values.

Holland et al. provide additional support for this conjecture. Their study differed a fair bit from that of Mikkelson et al., regarding their choice of other variables to control for. Yet it supported the same general conclusion: more unequal countries have more species headed toward extinction (i.e., plant and vertebrate species that are "threatened" according to the IUCN). Mikkelson et al. and Holland et al. both controlled for the total number of plants and vertebrates (threatened plus non-threatened), human population size, and gross domestic product (GDP) per capita corrected for the differential purchasing power of a dollar in different countries (purchasing power parity, or PPP). However, unlike Holland et al., Mikkelson et al. also controlled for geography by including a dummy variable for each continent. For example, if a country is in Asia, they assigned a value of 1 to the "Asia" dummy variable; if not, they assigned a value of 0 to that variable. They also controlled for one aspect of political history, through another dummy variable denoting whether or not each country is ex-communist or not. Unlike Mikkelson et al., Holland et al. controlled for a measure of environmental governance, the proportion of vertebrate species that are endemic (i.e., limited to one country only), and each country's development category according to the United Nations. Despite employing this distinct set of control variables, Holland et al. confirmed Mikkelson et al.'s finding of a statistically significant, positive link between economic inequality and biodiversity loss.

Future country-level studies of equality-biodiversity relationships can have the best of both worlds: bigger sample sizes than Mikkelson et al.'s or Holland et al.'s, but more reliable inequality data than the SIDD-3 used by Pandit and Laband. This is because, while the PIP has removed all versions of the SIDD from the web, Solt has made a new and improved inequality data set available (the Standardized World Income Inequality Database, or SWIID). Although the SWIID includes some interpolated values, it includes no gross extrapolations such as the Barbados example discussed above (Solt, 2009). The latest version of the SWIID includes Gini estimates for 4,549 country-year combinations. In addition to better inequality data, future equality-biodiversity studies can also draw upon the latest updates and refinements of the IUCN Red List.

Figure 2 offers a preview of such studies. Derived from the 2011 versions of both the SWIID and the Red List

See myweb.uiowa.edu/fsolt/swiid/swiid.html and www.iucnredlist.org/about/summary-statistics.

, Figure 2 shows a strong positive relationship between economic equality and plant conservation status among 122 countries (Kendall's τ = 0.31). This relationship is highly statistically significant (p ''< 10‑6), and preliminary analysis indicates that it holds up after controlling for potentially confounding variables. As Figure 1 shows, in all countries with an equality index (one minus the Gini index of inequality) greater than 0.70, more than 60% of well-studied plant species are considered to be at "lower risk" of extinction by the IUCN. In fact, in the great majority of these most equal countries - 21 out of 23 - more than 80% of such plant species are relatively secure. This suggests that achieving high levels of economic equality within a given country suffices to protect most of the plant species within that same country.

Possible mechanisms for the equality-biodiversity connection

Though Mikkelson et al. (2007) reported evidence for a causal connection between economic inequality and biodiversity loss, they did not detail the mechanisms by which equality may influence biodiversity. In this section we will therefore briefly discuss a few factors that may, upon further investigation, prove to be important. A first and probably important factor is population pressure. In an analysis of the 2004 Red List, the IUCN emphasized human population growth as an important socioeconomic driver of other species" population decline (IUCN, 2004). Figure 3 shows a strongly negative connection between economic equality and human population growth (Kendall's τ = ‑0.35, p ''< 10‑8). This inverse relationship holds up after controlling for per-capita income.

How might equality slow human population expansion? We hypothesise that gender equality will figure more prominently in the answer to this question than will other aspects of economic or political equality. Engelman (2008) identified gender equality as a key prerequisite - along with access to safe and effective contraception and abortion - to stabilising human population size. Gender equality also has at least one other advantage that benefits both human and non-human species: i.e., lower carbon emissions (Ergas and York, 2012).

A second possible mechanism for the equality-biodiversity link is the role of equality in promoting good governance. For example, Stiglitz (2012) stresses the importance of equality for guaranteeing access to justice. As we discuss below, a fair and efficient justice system may be a prerequisite for the effective management of environmental problems. In addition, Solt (2008, 2010) shows that economic equality enhances citizens' levels of political interest, political discussion, and electoral participation. We conjecture that such civic engagement induces governments in more equal societies to protect biological diversity more effectively, through conservation and restoration of habitat, reduction of pollution, and regulation of hunting and gathering.

A certain level of equality also seems necessary for successful community-based management of renewable natural resources (Ostrom, 1990). Natural resource management experiments in developing countries provide a particularly clear illustration of this. Whether for social forestry, the management of wildlife, protected areas, land ownership, or coastal fisheries, levels of equality affect poor rural stakeholders" access to biological resources, and the security of this access over time as the operators of globalised commodity chains exploit these resources ever further afield and more intensively.

Without sufficient levels of equality, the most disadvantaged stakeholders often lack the legal means required to secure long-term exclusive access to the biological resources vital to their welfare, because of either problems of access to land, the status of the resources themselves, the limited attention given to customary law in relation to written law, informal advantages granted to the most powerful companies or collusion between major economic actors and political leaders. For example, the development of agriculture (soybean, cattle ranching) in the Amazon, the major plantations in Indonesia, or the expansion of agricultural land into African savannah all reveal a transformation of natural rural landscapes composed of family farming areas with low externalities and considerable natural infrastructure into agricultural systems made up of large farms with high externalities and limited natural infrastructure. These situations have an adverse impact on biodiversity.

Socio-economic inequalities thus depress biodiversity through the "crushing" of small rural stakeholders due both to their relative weakness (less formalized, poorly respected rights, inferior social status, cultural stigmatisation, limited negotiating capacities) and to an effective coalition between major farmers, industries and politicians (one-sided resource exploitation contracts, large-scale land leases, assumption of risks and guarantees favouring major national and international stakeholders, weak trade unions and little representation of small farmers, etc.). For poor rural stakeholders, these inequalities result in land insecurity, unpredictability and a lack of transparency regarding access to resources. They diminish their capacity for self-organization, encourage the individualistic race to appropriate resources and limit the benefits and possibility of improving the sustainability of production systems.

Integrating economic equality into conservation practice

Conservationists tend to focus on mitigating proximal causes of biodiversity loss, chief of which is habitat destruction for agriculture and aquaculture (Salafsky et al., 2008). The equality-biodiversity connection discussed herein calls for greater attention to more distal socioeconomic causes - and ultimately to cultural causes. See White (1967) for an early, and now classic, cultural explanation of environmental destruction.

As discussed earlier, slowing growth in human numbers may be an important part of the mechanism by which equality mitigates species loss. It may also serve as a bridge between political economy and processes more familiar to conservation practitioners. Other pathways by which equality favours biodiversity take on special significance in the current context of the domination of concepts and instruments based on the economic value of biodiversity - especially economic assessments of environmental services and payments for environmental services - which tend to relegate approaches based on rights and statuses to the sidelines.

One of the first lessons to be drawn is that approaches based on the economic value of biodiversity must be systematically accompanied by a reduction in the political weakness of rural producers and direct users of ecosystems, by working on their rights of access to resources, their representation, and their capacities for negotiating and controlling local resources. Failing this, unequal dynamics result in greater insecurity for many local stakeholders, the rapid development of production systems with high profitability and externalities and an increase in adverse environmental and social impacts. A second lesson is linked to the fundamental inequality between the rich, who are often urban, and the rural poor: the former have the privilege of being able to shop independently of the state of local resources, with commodity chains moving around the world as ecosystems are depleted and opportunities provided by the weakest rights and regulations. Reducing this inequality of access and the associated biodiversity loss implies combining scales of action: for example, organizing sustainable local production systems for certified globalized suppliers; and reducing the relocation of urban supplies and better connecting cities to their peripheral rural areas.

A third lesson is that large-scale capitalistic production and exploitation must meet a rise in opposition and whistle blowing, as well as a consolidation of environmental rights. Actions to finance large-scale plantations (oil palm, rubber trees, etc.) must thus give way to stronger regulatory safeguards, transparency, and assistance for civil society.

How to attain equality

How then should societies go about increasing economic equality? With regard to the consequences for human well-being, it does not seem to matter. Wilkinson and Pickett (2009) used Sweden and Japan, and Vermont and New Hampshire, to illustrate this point. Sweden and Japan rank among the most equal countries in the world, in terms of net income (gross income, minus taxes, plus government transfers). Likewise, Vermont and New Hampshire rank among the most equal states in the US. Sweden, Japan, Vermont, and New Hampshire all have high life expectancies, levels of trust between citizens, etc. Yet while Sweden and Vermont attain their high levels of equality through progressive taxation and government transfers, Japan and New Hampshire achieve it through more equal gross income.

Figure 1 suggests that the route to high levels of net income equality does not matter for biodiversity conservation either. All of the most equal countries shown in Figure 1 also have relatively good plant conservation status. Nevertheless, Wilkinson and Pickett (2009) argue that one route to equality would achieve its end more securely and permanently than tax and benefits policies. Governments can quickly undo progressive tax policies, and they often have. In contrast, if an economy underwent a wholesale shift from domination by corporations - an inherently inegalitarian form of business organization - to cooperatives, it would fundamentally change the nature of work and investment (Mikkelson, 2011). Such a shift would therefore have more staying power than policies governing individuals' taxation and benefits.

Capitalist firms - what most of us know as, and we are calling in this paper, "corporations" for short - rely on inequality for their very existence, and deepen it once they do exist. They rely on inequality because they presuppose a distinction between two kinds of people - those who already have enough money to survive, and can therefore invest an additional amount in the firm (the shareholders); and those who must instead sell their labour in order to survive (the workers). Corporations deepen this initial inequality because they put the shareholders, instead of the workers, in the "driver's seat". It is the shareholders, rather than the workers, who ultimately control the corporation. And it is the shareholders, rather than the workers, who reap the profits which, unlike wages, have no pre-established upper limit. Of course, some corporations go out of business, causing their shareholders to lose some of their money and their workers to lose their jobs. But on average, corporations make more money for shareholders than they lose. Otherwise, only extreme risk-lovers would invest, and the stock market would collapse for good (Schweickart, 2011).

In contrast, worker cooperatives foster economic equality, in at least two ways. First, the profits go to the relatively poor workers, rather than to the relatively rich shareholders. Second, such co-ops operate democratically: the workers ultimately control the firm, and each has an equal vote. When workers decide on wages, they do elect to pay executives more than others, because they have an incentive to attract and keep managerial "talent" so that the firm succeeds, and its workers thus keep their jobs. But workers do not vote to pay executives hundreds of times more than others in the same firm. For example, in 2010 the highest-paid executive in the Mondragon federation of Spanish worker cooperatives earned just eight times the lowest wage in Mondragon (Ramesh, 2011). In contrast, by the early 21st Century the ratio between the highest and average wages in large capitalist firms had reached nearly 20 in Spain, not to mention over 500 in the United States (Bruce et al., 2005).

Despite the egalitarian advantages of co-ops, most firms are corporations, and most people work at the latter. Many have assumed that some kind of competitive disadvantage must explain the relative paucity of worker-controlled firms. However, the empirical record shows decisively that co-ops actually out-compete otherwise comparable corporations (Dow, 2003). To use a biological analogy, co-ops have a lower "death rate" than corporations. However, co-ops also have a much lower "birth rate", mostly due to inadequate investment. The only solution to this long-standing problem seems to be public investment. In other words, if co-ops are to take over the economy, governments must replace stock markets as the main source of capital for new firms (Schweickart, 2011).

For some, this would raise the spectre of central planning, still feared two decades after the collapse of the Soviet Union. However, it is one thing for governments to provide initial investment funds, and another for them to unduly control the firms they fund. The whole idea of a co-op is that its members (along with the market for its goods or services) control its behaviour. Another suitable guarantor of de-centralization would be to place most initial-investment decisions in the hands of local public banks, whose officials would be democratically accountable to the citizens of individual municipalities, rather than to a central government alone (Schweickart, 2011).


In this chapter we have reviewed work to date on the link between inequalities and biodiversity loss, discussed some possible mechanisms by which economic equality may benefit biodiversity conservation, suggested ways to integrate equality concerns into the conservation agenda, and discussed worker control of firms as a promising route to equality. We conclude that equality does seem to have an important relationship to biodiversity. This relationship bears further study and action at various levels from the local to the global. In particular, social and environmental activists should heed the equality-biodiversity connection, and work together to transform economies in a way that distributes resources more equitably both within the human species, and between humanity and the myriad of other species with a rightful claim to life and to flourish on Planet Earth.

In addition, official development assistance should aim to improve equality through the conservation projects it supports, and urge recipient countries to do the same. For funders increasingly concerned about demonstrating the effectiveness of their action and setting clear objectives, enhancing equality also presents the advantage of being measurable in the long term (for example using indicators such as the Gini index). Consequently, the introduction of at least one equality target in the post-2015 development objectives and/or in future sustainable development goals is imperative.

Equality and Plant Conservation by Countries

Documenting the link between economic equality and biodiversity conservation demands the collection and construction of comparable data sets such as the Standardized World Income Inequality Database, or SWIID.
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Equality and Plant Conservation by Countries

Documenting the link between economic equality and biodiversity conservation demands the collection and construction of comparable data sets such as the Standardized World Income Inequality Database, or SWIID.
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Demographic pressure, a product of inequality

Income equality, compared to the effect caused by income level, tends to have a stronger and more sustained impact on slowing a country's population growth. It also tends to make citizens more interested in public affairs, including the protection of biodiversity.
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