1 Introduction

Some of England’s most ecologically valuable natural environments are situated within common lands. While various waves of enclosure have reduced their extent, up until relatively recently, those that did remain were regulated by a set of stable institutions with ancient origins; with rights and duties falling on owners and rights holders and enforced through common law and the manorial court system. The rights system governing the commons had multiple aims, including economic output, equitable access, and community harmony and environmental sustainability (see Rodgers 2010; Winchester and Straughton 2010; Rodgers et al. 2011; Hodge 2016).

However, in 1965 the commons of England and Wales suffered a policy shock in the form of the Commons Registration Act 1965 that led to circumstances similar to Hardin’s (1968) classic allegory of the Tragedy of the Commons. Specifically, it led to a situation where the sum of individual grazing rights were often far in excess of the carrying capacity of the common land, but there was no formal legal mechanism to restrict access to rights holders. In addition, some areas of land were no longer grazed due to difficulties in building and maintaining infrastructure such as fencing and cattle grids, leading to biodiversity loss and weed infestation (Natural England 2009a).

Within the institutional vacuum generated by the Commons Registration Act 1965, a number of commons associations were formed, often from the remnants of the pre-existing manorial institutions.Footnote 1 These voluntary groups were set up by commons rights holders themselves. They had no state authority and relied on their members to agree upon how the common should be managed. Only with unanimous agreement were they able to enter into legally binding agreements or guarantees (Defra 2017).

The policy shock generated by the Commons Registration Act 1965 provides an opportunity to test whether the voluntary commons associations that were formed in its wake were able to deliver sustainable grazing outcomes. We consider the results to be important to both the literature evaluating the effectiveness of voluntary associations and agreements to deliver improved environmental outcomes and to the commons literature.

Starting with the empirical and experimental literature on voluntary associations and agreements, results concerning their effectiveness in delivering improved environmental organisations appear inconclusive (Kotchen 2013; Schleich et al. 2016; Gallier et al. 2017; Kesternich et al. 2017). This is partly driven by the fact that many voluntary environmental organisations have multiple objectives. For instance, as noted by Baland and Platteau (1998) and Tachibana and Adhikari (2009), community values such as identity may be placed above sustainable resource management goals.Footnote 2 Indeed, while collective action is often necessary, it is not sufficient in itself for generating sustainable environmental outcomes. Another reason for the mixed results relates to significant empirical challenges, including the need to obtain accurate data on environmental performance and to address issues associated with selection bias that are likely to loom large in the formation of voluntary environmental associations (Rustagi et al. 2010; Kotchen 2013).Footnote 3

Currently, much of commons literature employs case-study methodology (Poteete and Ostrom 2008). While the case-study method is undoubtedly rich in its insights and allows for the nuances of place- and time-specific processes to be uncovered, the data derived from case studies are not always suitable for hypothesis testing and are limited in their external validity (van Laerhoven 2010). Larger N-studies that allow for quantitative analysis are therefore highlighted as a means to complement the insights from case-studies and contribute to the commons literature (e.g. van Laerhoven 2010; Coleman 2011).

The second reason why these results are important is that they can help to shed light on the role of the state in relation to the formation and effectiveness of voluntary environmental organisations. Some, such as Mansbridge (2014), argue that the state is necessary to promote voluntary group formation and enable them to continue to be effective.Footnote 4 In terms of its necessity for enabling the formation of voluntary groups, Mansbridge (2014) argues that the state is needed to threaten to impose a governance solution if local parties cannot agree to come together—analogous to the ‘bargaining in the shadow of the law’ literature that sees parties voluntary agree on an outcome in the knowledge that a decision will be made for them if they do not (Mnookin and Kornhauser 1979). In terms of the voluntary association’s continued effectiveness, Mansbridge (2014) argues that recourse to an external sanctioning authority is necessary as purely local sanctions will be insufficient to protect natural resources. This contrasts with some of the empirical literature that has shown that local groups who did not receive state support had improved environmental outcomes. For instance, Tachibana and Adhikari (2009) found that community based management groups in Nepal who did not receive official support had better natural resource management outcomes than those who did. Ito (2012) has also found similar results for community irrigation organizations in rural China. We also hope that our results add to the emerging field experimental literature on common pool resource management that primarily aims to investigate the crowding out effects of centralised interventions (see Vollan 2008; Velez et al. 2010; Lopez et al. 2012; Santis and Chávez 2015).

The remainder of this paper is as follows. In Sect. 2, we provide an outline of the institutional framework of the commons of England, including a brief account of how the commons associations function. In Sect. 3 we present our data and empirical methods. In Sect. 4 we present our results and in Sect. 5 we conduct a number of robustness checks. In Sect. 6 we discuss the importance of our results, both in terms of the literature and policy implications, which is then followed by a brief conclusion.

2 Institutional Environment

In England, commons are privately owned parcels of land where third parties also have legally recognised use rights. They currently make up approximately 3% of total land area, and while they are scattered across the country; there are large concentrations in the northwest, southwest and southeast (see Fig. 1). Up until the Commons Registration Act 1965, commons were underpinned by a system of property rights where the lord of the manor owned the land and the local community (including farmers) held use rights that were enforced through manorial courts and common law (Rodgers et al. 2011). Within this legal framework, the rules of levancy and couchancy and stinting were practiced, along with the customary law principle of ‘good neighbourhood’, which provided a reflexive governance regime that is widely considered to have encouraged sustainable grazing practices (Bailey 2010; Rodgers 2010; Winchester and Straughton 2010; Rodgers et al. 2011; Hodge 2016). In terms of livestock, there were two specific mechanisms that encouraged sustainable practices. The first was the rule of levancy and couchancy that required commoners to only graze as many livestock on the common as could be kept over the winter months. The second was the practice of stinting, which consisted of grazing rights being defined by a fixed number of animals that could be adjusted in response to environmental factors.Footnote 5

Fig. 1
figure 1

Common land in England

However, the Commons Registration Act 1965 required rightsholders to register their nominal access rights, that could then lawfully be unabatedly enforced regardless of the environmental conditions. This legislative change led to the discontinuance of the common law principles of levancy and couchancy and stinting from being legally binding.Footnote 6 This often saw the sum of individual grazing rights being far in excess of the carrying capacity of the common land, but there was no formal legal mechanism to restrict access to rights holders as before. Additionally, registration of common rights under the Act led to under-grazing in parcels of common land where there were now difficulties in investing in communal grazing infrastructure due to the breakdown of the previous institutional arrangement of managing common lands (Williams 2006; Natural England 2009b). The Commons Registration Act 1965 can therefore be seen to have effectively severed previous existing links between principles of sustainable management and common property rights (Rodgers 2010). While the UK government aimed to correct for the perverse outcomes generated by the Registration Act 1965 with the Commons Act 2006,Footnote 7 in the intervening period (the timeframe which is the focus of this study), persistent over-grazing in upland commons and under-grazing in lowland commons were highlighted as a severe threat to biodiversity (Short 2000; Natural England 2009b).

Following the shock generated by the Registration Act 1965, a number of voluntary commons associations were established across the country, where members agreed upon how the common should be managed and how their rules could be enforced.Footnote 8 Despite their voluntary nature, there is anecdotal evidence to suggest that they played (and continue to play) an important role in achieving sustainable land management on the commons where they operate. For instance, Rodgers et al. (2011) assessment of Eskdale Common (see Fig. 1) is that the commons association is the main management institution, including in terms of the design and enforcement of stocking rules that are refined and adapted to accommodate change. They found that many of the grazing rights follow pre-existing customary practices. In this respect they found that the commons register is largely irrelevant to graziers when calculating their use rights on the common, illustrating ‘the secondary role that property law structures have on environmental management in the case study’ (Rodgers et al. 2011: 102). Like many other commons in England, Eskdale is party to an agri-environmental agreement, and here they found that not only did the commons association help negotiate and secure the agreement but also administer it effectively, including dealing with potential free-rider activity and disputes among commoners. In addition to the presence of agri-environmental agreements, Eskdale common is also within the boundaries of a Site of Special Scientific Interest (SSSI) which places special obligations on landholders to protect the natural environment, which also needs to be accounted for when evaluating the effectiveness of the commons association.Footnote 9

While the case of Eskdale common suggests that voluntary commons associations can be effective tools for sustainable natural resource management, up until now, it is not known whether this is an isolated case or evidence of a more systematic relationship. Furthermore, given the regulatory and institutional overlap that often exists within the commons of England, it is not clear what might be driving the environmental outcomes. If a robust systematic relationship can be established, it would provide valuable insights to the literature. It would also provide important insights for policy makers on whether voluntary associations can be left alone to deliver sustainable grazing outcomes or whether direct regulatory measures are necessary. Therefore, the remainder of this manuscript is dedicated to assessing whether voluntary commons associations are capable of achieving sustainable outcomes.

3 Data and Methods

We use historical spatial data on commons and land use outcomes sourced from the Biological Survey of the common lands in England (Defra 2012) and from the annual Farm Business Survey (Ministry of Agriculture, Fisheries and Food 2010) to investigate whether management by local commons associations is systematically associated with more sustainable grazing outcomes. We use two-stage least squares regression analysis to examine if commons associations have an effect on more sustainable grazing outcomes using economic heterogeneity as our instrumental variable.

3.1 Data Sources

3.1.1 The Biological Survey of the Common Lands in England

The biological survey of the common lands in England was compiled over a decade (1982–1993) by the Rural Surveys Research Unit at Aberystwyth University but only recently made publicly available. The survey contains extremely valuable biological, geographical, and regulatory data for 7052 parcels of common land sourced from the registers of common land, archives and field surveys.Footnote 10 716 parcels of common land in the biological survey include field survey evaluations on grazing intensity based primarily on vegetation condition and quantified according to a six-category classification. A score of 1 or 2 was given to parcels of common land with low grazing intensity. A score of 3 or 4 was given to parcels of common land with medium grazing intensity. A score of 5–6 was given to parcels with high grazing intensity. According to Aitchison et al. (2000), commons judged as having low-grazing intensity can be considered to be under-grazed and commons judged to have high intensity can be considered overgrazed. We transform this measure of grazing intensity into a binary variable with 0 representing either under- or over-grazed intensities and 1 representing sustainable grazing outcomes. Our rationale for this comes from the poor environmental outcomes associated with both under-grazing and over-grazing. For example, under-grazing tends to lead to species invasion and a loss of biodiversity. Similarly, over-grazing tends to reduce vegetation, expose underlying soil and cause soil erosion (Williams 2006).

Whether parcels were governed by local commons associationsFootnote 11 were recorded for all 716 parcels of common land with a total of 48 parcels being recorded as governed by voluntary local commons associations during the survey period. Additional variables of interest in the survey include: whether or not there were disputes over rights of common among commoners; the number of grazing rights per hectare; the number of different types of rightsFootnote 12 held; elevation; dominant habitat and livestock-type; and whether or not the parcel of common land falls partially or fully within the boundaries of an Area of Outstanding Natural Beauty (AONB), a Site of Special Scientific Interest (SSSI) or a National Park.

3.1.2 The Farm Business Survey

The farm business survey (FBS) is an annual survey that collects data from approximately 2300 farms in England and Wales. The survey covers the physical, environmental and economic performance of farm businesses (Defra 2017). We use spatial data from the farm business survey over the period 1982–1993 to construct measures of user attributes for our econometric analysis. Specifically, we construct measures of farmer age, farmer education, farm size, farm income, and environmental payments received (see Table 8). We also calculated our instrumental variable, non-livestock income heterogeneity of farms (economic heterogeneity), using data from the Farm Business Survey. To construct our measures, we first categorized individual farms by the lowest local unit of local administration in England (LAU1) for the years 1982–1993. For instance, taking our instrumental variable (economic heterogeneity) as an illustrative example, we calculated the Gini coefficient—a widely accepted measure of economic inequality—of non-livestock farm income for each LAU1 polygon over the period 1982–1993. We then averaged Gini coefficients for each LAU1 polygon over the period 1982–1993 before overlaying all parcels of common land. We assigned the Gini coefficient for each LAU1 polygon to the parcels of common land spatially located within respective LAU1 boundaries.Footnote 13

3.2 Econometric Estimation

We begin by estimating the relationship between the management of local commons and sustainable grazing outcomes using a linear probability model. While a basic linear probability model is instructive for determining whether a statistical relationship exists between voluntary commons associations and sustainable grazing outcomes it has its limitations. Most importantly, there is likely to be endogeneity between the existence of commons associations and environmental outcomes. That is, it may be that better organized and more community spirited commons may be more likely to form voluntary commons associations. In such a situation, it becomes difficult to determine whether it is the voluntary commons associations themselves producing better environmental outcomes or some other underlying characteristics of the common. In such a case, the linear probability estimation will produce biased estimates because the variable capturing whether the common is managed by a voluntary commons association is likely to be correlated with the error term of the regression. In response to the potential problem of endogeneity, we employ a two stage least squares model to estimate a linear relationship between sustainable grazing outcomes and voluntary commons associations.

3.2.1 Linear Probability Regression Analysis

We estimate the relationship between the management of local commons and sustainable grazing outcomes using a linear probability model that takes the following form:

$$ g_{i} = \alpha_{0} + \beta_{1} C_{i} + X_{i}^{\prime } {\Upphi } + \varepsilon_{i} $$
(1)

where gi is a binary measure for sustainable grazing outcomes for individual common i, Ci measures whether individual common i has a voluntary commons association in place for the period of measurement, and X i is a vector of control variables.Footnote 14 We choose a linear probability model to produce results that are more consistent with the two stage least squares estimation below. In selecting our control variables, we draw on Ostrom’s (2009) socio-ecological systems (SES) framework that identifies systems and sub-systems that affect the likelihood of resource users self-organising to achieve sustainable outcomes. Ostrom’s SES framework consists of core sub-systems covering users, governance systems and resource systems and units which interact to produce a range of sustainability outcomes. These core sub-systems are further disaggregated into second-level variables.

We follow Ostrom’s SES framework in grouping our control variables according to sub-system.Footnote 15 Starting with user-attributes, we include the number of users, farmer age, education, income and farm size. For governance systems, we include whether or not there were disputes over rights of common among commoners, the number of grazing rights per hectare, the number of different types of rights held, whether or not the parcel of common land falls partially or fully within the boundaries of an Area of Outstanding Natural Beauty (AONB), a Site of Special Scientific Interest (SSSI) or a National Park and average payments from the environmental sensitive areas (ESA) scheme. For resource systems and units, we include elevation, dominant habitat type, and livestock type.

3.2.2 Two-Stages Least Squares Regression Analysis

We employ a two stage least squares model to estimate a linear relationship between sustainable grazing outcomes and voluntary commons associations. The first and second-stage regressions are of the following form:

$$ C_{i} = \alpha_{0} + \gamma_{1} Z_{i} + X_{i}^{\prime }\Phi + u_{i} $$
(2)
$$ g_{i} = \alpha_{0} + \beta_{1} C_{i} + X_{i}^{\prime }\Phi + v_{i} $$
(3)

In these two equations, gi is the measure for sustainable grazing outcomes, X i is a set of exogenous control variables (as outlined above), Ci is the endogenous measure for whether a voluntary commons association in place, Zi is the instrumental variable (economic heterogeneity, which is discussed below), and ui and vi are the econometric errors, which contain unobservable factors that can either be related to the formation of voluntary commons associations, sustainable grazing outcomes, or both.

The parameter of interest is the second stage parameter \( \beta_{1} \), which aims to measure the causal effect of commons associations on sustainable grazing outcomes. For this parameter to be identified, the instrument of economic heterogeneity must be both ‘relevant’ and ‘valid’. Specifically, our instrument must be both correlated with the establishment of commons associations and have no effect on sustainable grazing outcomes other than through the establishment of commons associations.

Starting with the ‘relevance’ requirement, theoretical and empirical evidence suggests that we can expect economic heterogeneity to be associated with the establishment of local commons associations. While it is acknowledged that there is debate over the role that economic heterogeneity plays in relation to the promotion of community organizations, there seems little doubt that it is an important factor (e.g. Johnson and Libecap 1982; Tang 1994; Ruttan and Borgerhoff Mulder 1999; Vedeld 2000; Varughese and Ostrom 2001; Dayton-Johnson and Bardhan 2002; Kurien and Dietz 2004; Ruttan 2008; Andersson and Agrawal 2011; Ito 2012). In the context of the English commons we posit that economic heterogeneity allows for some ‘privileged’ commoners to be able to more easily absorb the start-up and running costs associated with a local commons association, and as will be seen in our results (Table 3), our measure of economic heterogeneity is strongly positively correlated with local commons associations.Footnote 16

Turning to the second requirement of a good instrument, ‘validity’. This requires that economic heterogeneity should exclusively affect sustainable grazing outcomes through its first stage impact on the establishment of commons associations. We consider this to be a defendable assumption in our case, as it is not apparent how economic heterogeneity (as we measure it—see below) could play a role in sustainable grazing outcomes, other than through better community organization that is manifested by the establishment of a commons association. While it is true that income levels may affect environmental preferences or capacity to undertake investments that protect the environment, there is no apparent reason why economic heterogeneity should. Given that economic heterogeneity may be linked to concentration of common use rights that may in turn be linked to grazing outcomes, we construct a measure that de-links this potential relationship.Footnote 17 We do this by excluding income derived from livestock in our measure of farm income that is used to construct our measure of economic heterogeneity. By excluding all income generated from livestock (whether on private or common land) we hope to exclude the potential for a direct relationship between income heterogeneity and management of common land, thus providing us with an instrument that should be valid.Footnote 18 As an additional check, we estimate an overidentified model using generalized method of moments (gmm) estimation. To do this, we disaggregate our economic heterogeneity variable into two components: crop income and off-farm income. We calculate the gini coefficient for each component and include the two measures of economic heterogeneity as our instruments. This allows for us to test the validity of our instruments using the Hansen J-statistic test.

4 Results

4.1 Summary Statistics

Table 1 reports summary statistics for our measures of sustainable grazing and local commons associations, as well as our user-, governance-, and resource-attribute variables. Summary statistics are also presented for our instrumental variable: economic heterogeneity. In our sample, we find that 331 (46%) of our parcels of common land are grazed sustainably and that 385 parcels are either under- or over-grazed. We also see that 48 parcels of common land are managed by a commons association.

Table 1 Summary statistics

4.2 Linear Probability Model

As can be seen in Table 2, commons associations are consistently linked with sustainable grazing outcomes at the 1 percent significance level across all estimation specifications using OLS. The coefficient is also highly consistent across specifications. Beginning with our first specification which includes no control variables (column 1) we find that commons associations are 36 percentage points more likely to be associated with sustainable grazing outcomes. When we include user attributes in our model (column 2), we continue to find commons associations to be statistically significant at the 1% level and commons associations are 39 percentage points more likely to be associated with sustainable grazing outcomes. In column 3 we control for governance attributes and find that commons associations are now 33 percentage points more likely to be associated with sustainable grazing outcomes. Controlling only for resource attributes (column 4), we find that commons associations are 36 percentage points more likely to be associated with sustainable grazing outcomes. In our preferred specification (column 5), we include all user-, governance- and resource-attribute control variables and find that commons associations are 36 percentage points more likely to be associated with sustainable grazing outcomes.Footnote 19

Table 2 Linear probability regression results

4.3 Instrumental Variable Estimation

While the estimations above suggest a strong link between sustainable grazing and commons associations, they do not establish a causal relationship due to the potential for endogeneity. As discussed above, more cohesive and functional commons communities may be more prone to form commons associations. Therefore, we instrument for commons associations using a measure of economic heterogeneity (excluding livestock income).

Table 3 presents the results of an exactly identified two-stage least squares regression that mirrors the simple OLS regressions above; where in column 1 we do not include any control variables, in column 2 we include only our user-attribute variables, in column 3 we include only our governance-attribute variables, in column 4 we include only our resource-attribute variables, and in column 5 we include user-, governance- and resource-attributes. In terms of our first stage results it can be seen that our measure of economic heterogeneity is positively associated with commons associations across all specifications at the 1% statistical significance level. Indeed, the Angrist–Pischke (AP) F statistic has a value above 21 across each of the specifications suggesting that economic heterogeneity is an informative instrument (Staiger and Stocks 1997; Stock and Yogo 2005).

Table 3 Main results: two-stage least squares

In terms of the second stage, we find commons associations to be positively associated with sustainable grazing outcomes across all specifications, with generally higher coefficients but with lower significance levels compared to our OLS regression results.Footnote 20 The fall in statistical significance is a result of much larger standard errors compared to the simple OLS regressions (approximately 5 times larger). This is to be expected with two-stage least squares regressions, as only part of the variation in commons management is used to explain sustainable management outcomes. In our preferred specification, which includes user-, governance- and resource-attributes as controls, we find commons associations to be positively associated with sustainable grazing outcomes at the 5% level with a coefficient of 0.843. That is, our results find that commons that have commons associations are approximately 84 percentage points more likely to produce sustainable grazing outcomes. Importantly, this result stands while controlling for individual characteristics of farmers that use the commons, wider governance characteristics (including regulatory overlap such as commons being in national parks) and geographical and biological attributes of the commons themselves (including elevation).

5 Robustness

Our estimates above show that commons governed by voluntary commons associations are much more likely to achieve sustainable grazing outcomes. However, it is acknowledged that these results depend on our measure economic heterogeneity being a valid instrument. They also depend on our operationalisation of ‘sustainable grazing’. In this section we aim to demonstrate the robustness of our results. Firstly, we overidentify the estimated model by disaggregating our measure of economic heterogeneity into two separate instruments. Secondly, we estimate the relationship between voluntary commons associations and under-grazing and over-grazing using a multinomial logit regression. Thirdly, we estimate the relationship between voluntary commons associations and over-grazing only. Finally, we control for time stamps to take into account the fact that the data on sustainable grazing were collected over the course of a decade.

5.1 Overidentified Model

In an effort to test whether our instrument can be legitimately excluded from our estimated equation, we estimate an overidentified model using generalized method of moments (gmm) estimation. This allows for us to test the validity of our instrument (economic heterogeneity) using the Hansen J-statistic test. The Hansen J-statistic test is a heteroscedasticity robust joint null hypothesis test that the instruments are valid (e.g. uncorrelated with the error term). To do this, we disaggregate our economic heterogeneity variable into two components: crop income and off-farm income. We calculate the gini coefficient for each component and include the two measures of economic heterogeneity as our instruments. As shown in Table 4, we continue to find both measures of economic heterogeneity to be positively associated with commons associations across all specifications at the 1% significance level. We also continue to find commons associations to be positively associated with sustainable grazing outcomes at the 5% significance level. Turning to our results for Hansen’s J test statistic, we find p values of 0.454–0.603 across all of our specifications. We therefore do not reject the null hypothesis that our instruments are valid.

Table 4 Overidentified gmm regression results

5.2 Multinomial Logit Regression

As previously mentioned, in our main analysis we transformed the six-category measure of grazing intensity into a binary measure denoting sustainable grazing and unsustainable grazing (under- and over-grazing). As an additional robustness test, we make use of a more comprehensive distribution of our measure of sustainable grazing and investigate the statistical relationship between voluntary commons associations and grazing outcomes using a multinomial logistic regression. To do this, we collapse the six-category measure of grazing intensity into three categories: under-grazing (categories 1 and 2), sustainable grazing (categories 3 and 4), and over-grazing (categories 5 and 6). We do this for two reasons. Firstly, we require a base category of sustainable grazing for comparison. Secondly, not all categories had sufficient observations to be included individually.

Our results are presented in Table 5. We find that voluntary commons associations are associated with a decreased probability of there being over-grazing relative to sustainable grazing at the 5% significance level. We also find that commons associations are associated with a decreased probability of there being under-grazing relative to sustainable grazing at the 10% significance level. These results are robust to including user-, governance- and resource-attribute control variables and robust standard errors. Our results are consistent with our OLS and logistic regression estimations that use a binary variable of sustainable grazing.

Table 5 Multinomial logistic regression results—average marginal effects

5.3 Overgrazing

As discussed above, under-grazing imposes a threat to sustainable grazing practices for the commons of England and is therefore included in our measure for sustainable grazing outcomes in our main results. Under-grazing can lead to species infestation and is explicitly recognised as a threat to sustainable farming practices by a number of commons associations. One of the main causes for under-grazing is a lack of grazing infrastructure. For example, a report commissioned by Natural England (2009a) found that individual commoners in Exmoor were unwilling to graze some parcels of common land due to a lack of cattle grids, and that more generally a lack of fencing was a significant deterrent to individual commoners exercising their grazing rights. Investing in infrastructure (e.g. cattle grids, fences) can be often prohibitively costly for a given individual but could be an optimal strategy for the group as a whole.

Despite this, we acknowledge that over-grazing is most usually associated with the unsustainable management of commons, as popularized by Hardin’s (1968) classic allegory. Therefore, we estimate the relationship between commons associations and overgrazing using the same exactly identified two-stage least squares approach as in our main results. As can be seen in Table 6, we find a negative and highly significant relationship. These results show that commons governed by voluntary commons associations are less likely to result in over-grazing. In our preferred specification, that includes all controls relating to user, governance and resource attributes, commons governed by voluntary commons associations are 94 percentage points less likely to result in over-grazing.

Table 6 Two-stage least squares results—overgrazing

5.4 Time-Stamps

As previously noted, our grazing intensity data were collected over a decade. To make sure that the period in time at which data were collected for a given parcel does not systematically affect our results, we re-run our exactly identified two-stage least squares regression estimations controlling for time-stamps denoting when the grazing intensity data were collected from each parcel. As can be seen in Table 7, our results continue to be statistically significant at the 1 and 5% significance levels when controlling for time-stamps.

Table 7 Two-stage least squares controlling for time stamps

6 Discussion

Using two-stage least squares regression analysis we have found that commons governed by voluntary commons associations are approximately 84 percentage points more likely to produce sustainable grazing outcomes than those that are not. These results hold while controlling for the individual characteristics of farmers that use the commons, wider governance characteristics (including regulatory overlap such as commons being in national parks) and geographical and biological attributes of the commons themselves.

The policy shock generated by the Commons Registration Act 1965 provided us with an opportunity to test whether the voluntary commons associations that evolved as a result of the shock were able to achieve sustainable environmental outcomes. Our findings therefore make a quantitative contribution directly to both the literature evaluating the effectiveness of voluntary associations and agreements to deliver improved environmental outcomes and to the largely case-study-based commons literature. As noted by Kotchen (2013), the results on the efficacy of voluntary approaches to environmental management have been mixed to date and the literature suffers from empirical difficulties, most notably poor measurement and selection biases. We have been able to deal with the measurement issue by using the recently released Biological Survey of the Common Lands of England that provided detailed and scientific assessment of grazing outcomes on a sample of commons. In relation to the potential for selection bias, we use an instrumental variable approach. We consider that these approaches in tandem enable us to deal with the main empirical problems and to make a claim that voluntary commons associations lead to more sustainable grazing practices.

Our study complements the rich detail of case studies of voluntary commons associations and sustainable natural resource management. For example, the previously mentioned case study of Eskdale Common by Rodgers et al. (2011) sheds light on both the place- and time-specific processes resulting in the formation of the Eskdale voluntary commons association and on the role that its voluntary commons association played in improving the sustainability of grazing practices. Although such case study approaches are incredibly important and necessary in order to improve our understanding of the commons and their management, they do not allow for hypothesis testing and are limited in their external validity (van Laerhoven 2010). By using a unique dataset of 716 parcels of common land in England, our study allows for the scaling-up of local-level findings such as that of Eskdale Common by testing the hypothesis that voluntary commons associations lead to more sustainable grazing outcomes at the national-level.

While voluntary commons associations were found to markedly improve environmental sustainability outcomes, it is also noteworthy that the majority of commons in our sample do not have them.Footnote 21 These results taken together suggest that while voluntary environmental associations can be effective when they exist, they are relatively rare. In terms of policy implications, this suggests that direct government action may still be necessary if widespread environmental improvements are to be achieved. However, governments should proceed cautiously as there is a growing body of experimental literature on common resource management (see Lopez et al. 2012; Santis and Chávez 2015; Velez et al. 2010; Vollan 2008; Cardenas and Stranlund 2000) that highlights the potential crowding-out effects of government intervention on intrinsic motivation to govern commons. Furthermore, the work of Dal Bó et al. (2010) has shown that exogenously imposed governance regimes can be far less effective than those developed endogenously through democratic processes.

As an alternative to direct government regulation, governments could aim to foster the establishment of voluntary environmental associations more widely. This would involve a thorough understanding of the structural impediments to the formation of voluntary associations. In the English context, some of the key impediments to the establishment of voluntary commons associations appear to be (relatively) high establishment and running costs. This is as establishing voluntary commons associations can be particularly complex and time consuming because of the need to secure the participation of all rights holders, whether they are active users or not: a problem that is made even more complex when rights registered under the 1965 Act have been subsequently sold with no requirement to inform the register of the new rights holder. Other impediments to collective management include the reluctance of some inactive graziers to allow new binding rules that they feared might prevent their dormant rights from being exercised at a later date (Rodgers et al. 2011).

It is hoped that some of the impediments to the formation of voluntary commons associations identified above will be addressed through the ongoing implementation of the 2006 Commons Act, in particular through the opportunity for commoners to establish Commons Councils without the need for unanimous agreement of all rights holders. Importantly this reform should reduce establishment costs by lowering search and negotiation costs (as not every single rights holder needs to be contacted and convinced to join the association for it to have binding rules), however it may increase them in other areas.Footnote 22

It is worth noting that while we have aimed to deal with endogeneity through the use of an instrumental variable approach, there may be unobservable characteristics among the members of the current voluntary commons associations that differ from those who are not, and this has the potential to bias our results. For instance, Dal Bó et al. (2010) found that those more likely to vote for voluntary governance mechanisms are more likely to act cooperatively in an experimental setting, while Rustagi et al. (2010) has shown that groups with a higher share of conditional cooperators are more likely to have better forest outcomes. These studies suggest there may well be unobservable characteristics that link voluntary commons associations to sustainable grazing outcomes that we have been unable to control for. Nonetheless, we consider that we have provided some useful evidence linking voluntary commons associations to better environmental outcomes. As outlined earlier, we note that the existing literature is mixed on this issue.Footnote 23 Ultimately, we hope that our results help researchers and policy makers find the best institutional arrangements to govern the commons.

When assessing our results in terms of their broader applicability, some discussion of the institutional environment that the commons associations are situated within is also necessary. While it is true that the Commons Registration Act 1965 led to a ‘direct’ institutional vacuum in relation to commons management, other governance measures were instituted, and the broader institutional structure of English law remained in place. In terms of the establishment of commons associations, while the government did not incentivise their formation through the threat of intervention if a voluntary agreement could not be reached (indeed the opposite occurred in that they were a response to the withdrawal of a government regulatory framework), it did incentivise their incorporation through the establishment of agri-environmental schemes. These schemes provided funds to farmers for delivering sustainable farming outcomes and were only accessible to common rights holders when they coordinated themselves. In this sense the government provided a ‘carrot’ for voluntary associations rather than a ‘stick’ (as proposed by Mansbridge 2014).

The second important institutional factor relates to the English legal system as a whole. Commons associations are unincorporated bodies that do not have the legal power to bind a dissenting minority and they are only able to make a binding agreement to regulate livestock through unanimous participation amongst rights holders (Rodgers et al. 2011). However, if consensus to form an association can be achieved, the members of the commons associations can enter into a legally binding agreement that enables non-compliers and defectors to be punished through the courts. Therefore, while the voluntary commons associations were unable to sanction non-compliers directly (other than through the use of social sanctions) they could use legal action (or threat of it) to enforce their rules. This highlights the potential importance of a well-functioning legal system in providing an ‘institutional infrastructure’ that enables voluntary environmental associations to continue to be effective in delivering environmental benefits once an agreement has been made.

7 Conclusion

The 1965 Commons Registration Act was a policy shock that led to the removal of the capacity of commoners to regulate the intensity of grazing via traditional legal means. In response to this shock a number of voluntary commons associations were formed. Using spatial environmental and socio-economic data, we investigate whether these voluntary commons associations were able to deliver improved environmental sustainability outcomes. Using an instrumental variable approach, we find that commons governed by voluntary associations were approximately 84 percentage points more likely to produce sustainable grazing outcomes. These results are robust to the existence of a variety of controls, including the existence of overlapping institutional frameworks. Our results make an important quantitative contribution to the literature evaluating the effectiveness of voluntary associations and agreements to deliver improved environmental outcomes. At the same time, our results complement the rich detail of case studies found in the commons literature by testing the hypothesis that voluntary commons associations are causally related to more sustainable grazing outcomes at the national-level. In terms of policy implications our results are more mixed. This is as while our results show that voluntary associations can deliver more environmentally sustainable outcomes, voluntary associations themselves are relatively rare. This suggests that either direct government regulation is necessary (with the risk of crowding out current informal practices and intrinsic motivation) or governments must be more proactive in encouraging the formation and operation of voluntary commons associations by lowering establishment and running costs.