Abstract
Enterprise zone policy is a potential tool for the regeneration of distressed areas, based primarily on tax incentives to businesses locating in the target areas. The tool has been tested in several countries over more than 35 years but there is no consensus on whether or not it is effective and efficient in creating jobs and reducing unemployment in targeted localities. This paper reviews seminal enterprise zone evaluations in the UK, USA and France. More than one-half of the studies reported local employment benefits but the others reported none and information is limited on what affects policy success. The paper argues that typically narrow-focus research designs and a-theoretical evaluation have contributed to the lack of consensus and policy insight, potentially exacerbated by non-exact data. It proposes richer evaluations with explicit theoretical frameworks, such as the one presented in the paper, more comparative work and the use of more accurate data.
Introduction
Enterprise zone policy aims to stimulate economic development in localities where market forces have not been able to bring about regeneration. Its central feature is the award of tax incentives to businesses within designated zone locations, typically for capital investment or employment. Simplified regulation may also be included, notably on land use planning. The policy has operated in various forms and countries for more than 35 years. Recently, OECD (2016) identified 16 OECD countries operating special economic zone policies, including enterprise zone policies in the UK, the USA, France, Korea and Poland. 1
This paper reviews seminal evaluations of the local employment impacts of enterprise zones in the UK, the USA and France. 2 Despite a significant evaluation literature, no consensus has emerged on whether or not enterprise zones are effective or efficient in delivering local employment benefits. On the one hand, some researchers have made negative summaries, such as: ‘enterprise zones have not been successful’ (Peters and Fisher, 2002); ‘at least at the historical level of expenditures, enterprise zones are not an effective way of increasing the probability that the residents of distressed areas are employed’ (Elvery, 2009); and ‘while enterprise zones have been studied extensively, there is little evidence that they have succeeded’ (Greenbaum and Landers, 2009). On the other hand, more than one-half of the seminal papers reviewed here have identified positive local employment impacts from enterprise zone programmes, and several suggest that reasonable value for public money has been obtained (Busso et al., 2013; Erickson and Friedman, 1990a, 1990b, 1991; Freedman, 2012; O’Keefe, 2004; PACEC, 1987, 1995; Papke, 1993; Rubin, 1990; Rubin and Wilder, 1989). This paper considers what might be behind the discrepancies in findings on the local employment impacts of enterprise zones and how future research might deliver greater consensus and policy insight.
The paper starts by describing the objectives and origins of enterprise zone policy and its operation in the UK, USA and France. It then offers a theoretical framework to illustrate a range of processes through which enterprise zones may influence local employment, suggesting issues that should be considered by evaluation. Evaluation findings are then reviewed on employment impacts and the factors influencing them, including consideration of evidence gaps. Some data weaknesses are then highlighted. The paper concludes with a call for more theoretically based evaluations, more comparisons across zone designs and contexts, and the use of richer and more precise data.
Objectives, origins and operation of enterprise zone policy
Objectives
Governments tend to view enterprise zone policy as a means of stimulating growth in places in which market forces have been unable to secure recovery from shock, recognising a potential to improve national efficiency and equity as well as local outcomes. Its appropriateness to the challenge largely depends on how far it can remedy the market and institutional failures underlying the local problems. The spatial mismatch hypothesis suggests that unemployed inner-city job seekers may lack access to non-local job vacancies – for example because of missing information, networks, or transport (Gobillon et al., 2007; Ihlanfeldt and Sjoquist, 1998). Renewed labour demand may be impeded by barriers to business investment, such as negative externalities from past decline (e.g. loss of skills and work readiness, out-migration of skilled workers); a poor match between the competences of displaced workers and new jobs; downwardly sticky wages; or high local business tax rates. Property markets may leave local sites and premises redundant as a result of negative externalities from dereliction; lack of information on property values following redevelopment; indivisibilities and scale economies in development; and costly, slow and uncertain planning procedures (PACEC, 1995).
Enterprise zones seek to respond by using investment and employment subsidies for businesses located in zones together with property development subsidies and regulatory changes. They may be able to address labour market failures by creating jobs in locations where they can be accessed by job seekers; increasing wages to market clearing levels; removing negative externalities affecting worker competences and business perceptions of investment opportunities; and reducing local business taxes. They might address property market failures by raising the rate of return on property investment and reducing planning constraints. The policy can be seen largely as a demand-side, place-based approach. It can be contrasted with people-based policies (focused on increasing employment opportunities wherever people live) and supply-side place-based policies (e.g. training and job matching for displaced workers).
Origins and operation
The origins of enterprise zone policy lie in a 1977 address by Sir Peter Hall to the British Royal Town Planning Institute in which he suggested an enterprise zone experiment as a possible ‘last ditch’ solution to Britain’s inner-city crisis. It would pare back business taxation and regulations to a minimum in a few inner-city locations with severe unemployment and derelict land so as to attract business relocations and stimulate small firm development (Hall, 1982: 417). The relocations would take activity from other places, but they could deliver a net benefit by drawing unemployed inner-city residents into the labour market as displaced workers in more prosperous areas found alternative jobs. 3 The zones might also generate new activity by stimulating small business creation and growth, and gradually progress inner-city residents up a skills and incomes ladder.
The idea was taken up by the UK’s Thatcher government, which established 23 enterprise zones between 1981 and 1984. 4 The zones offered business taxation incentives and simplified planning regulations for 10 years in a mix of inner city, suburban and rural areas with high unemployment and vacant sites. Further designations followed from the mid-1980s to 1996. The UK reintroduced enterprise zones in a modified form in 2012, designating 35 zones initially. The Mark II zones offer a lower value and duration of incentives, restrict benefits to small firms and new-to-zone activities (excluding local relocations), and target areas with capacity for growth in priority sectors as well as regeneration need.
US state governments started to create enterprise zones from the early 1980s and most states have operated zones since then, typically using mixtures of employment and investment incentives. In 2017, 21 states operated zones. 5 The US federal government has also been active, operating 40 Empowerment Zones, 20 Enterprise Communities and 40 Renewal Communities in the 1990s and early 2000s, and creating 22 Promise Zones in 2014. 6
The French government also operates enterprise zones. This was initially in the form of 100 Zones Franches Urbaines (ZFU), which ran from 1997 to 2014 in urban areas with very high unemployment, offering reduced corporate taxes, property taxes and social security contributions. The programme was extended until 2020 in the less generous form of Territoires Entrepreneurs.
Further details of the programmes are given in Table 1.
Key design features of enterprise zone programmes in the UK, France and USA.
Notes: aA number of states have tiered incentives that are available across the whole state but vary in value according to the level of distress of the county or locality. They are excluded from this table and paper, which focus on programmes that limit incentives to designated zone areas within the state. States operating tiered incentive programmes include Arkansas, Maine, Missouri, Oklahoma, South Carolina and Tennessee. bIn these states, firms benefiting from incentives do not have to be located within the enterprise zone but they should hire enterprise zone residents. cThis has a somewhat different focus compared with other state enterprise zone programmes because of its emphasis on higher education institution linkages. dThis refers to the Development Opportunity Zones. Wisconsin also operates Enterprise Zone Tax Credits but they are typically designated for individual, large-scale businesses rather than localities needing regeneration.
A theoretical framework for enterprise zone evaluation
Although some enterprise zone evaluations have followed comprehensive theoretical frameworks (Busso et al., 2013; PACEC, 1987, 1995), most of the employment-focused evaluations have concentrated on the relationship between zone status and headline employment outcomes. Richer evaluations will require more detailed theoretical frameworks. Figure 1 offers a framework exploring neoclassical firm and place equilibrium effects and the influence of factor mobility, substitution and price elasticity, although other theoretical views could be taken. 7 The processes in this framework may be influenced by differences in zone programme designs and contexts, and hence potentially help explain differences across the literature in evaluation findings.

A theoretical framework for investigating local employment and growth effects of enterprise zones.
The top of the figure illustrates channels through which enterprise zone incentives could increase employment and property demand. It classes the incentives into employment, capital equipment and real estate subsidies. A key channel involves reduced unit output costs for firms from employment and capital subsidies, and from real estate subsidies if the firm owns its own premises. The increased profitability may lead to net firm in-migration and enable pre-existing establishments to reduce prices or increase investment (in products, equipment, training, marketing etc.), hence increasing their competitiveness and stimulating expansion. This may increase demand for labour and property.
The framework suggests some potential mediating influences. If capital subsidies are large compared with employment subsidies then labour demand growth could be counterbalanced by capital–labour substitution, which could be a particular problem in manufacturing-dominated zones, since substitution may be easier in manufacturing than services. Incumbent establishments could also respond to increased profitability by distributing profits rather than reducing prices or investing, although limiting subsidies to new recruitment or new-to-zone firms might address the issue. 8 Third, reduced business operating costs could be capitalised by property owners in increased rents and prices, particularly if supply is constrained.
The bottom of the figure illustrates how increased labour and property demand, and increased returns on property investment brought about by real estate subsidies, may stimulate growth by increasing the effective supply of labour and land. 9 The emphasis is on reductions in long-term unemployment, which is seen as net of macroeconomic crowding out and hence as a national gain rather than a spatial redistribution. Self-reinforcing local agglomeration benefits could also be generated. 10 The framework also suggests a possible impact on equity as employment and income outcomes improve for poorer localities and people.
The framework also suggests some further potential explanations for the discrepancies that have emerged in enterprise zone evaluation findings. For example, new employment could go to inactive labour, commuters or in-migrants rather than the unemployed, and the extent to which this happens may be affected by local context (e.g. large urban areas may see more inward commuting). 11 Wage growth might also reduce employment growth, particularly in places and periods of constrained labour supply. 12 A displacement of long-term unemployment to neighbouring areas could also occur, which would be damaging if those areas also have high long-term unemployment. 13 The importance of these effects may vary with local context and with programme design, potentially helping explain variations in evaluation results across different programmes.
Key evaluation findings
Do enterprise zones increase local employment or reduce unemployment?
Table 2 provides summary information on the local employment findings of enterprise zone evaluations. It clearly reveals the discrepancies. Of 34 evaluations, 21 found that enterprise zone intervention increased employment or reduced unemployment, whereas 12 found that intervention had no impact on employment or unemployment levels. One reported quite mixed findings.
Employment impact findings of seminal enterprise zone evaluation studies.
Note: aThese are broad characterisations of the approaches with the purpose of highlighting key issues for obtaining high quality data. It is sometimes difficult to categorise the studies but the authors have made a judgement based on the information in the relevant publication. The characterisations provided do not fully capture the extent of any mismatches (e.g. differences between a minimal mismatch or a major mismatch). They also do not allow for the use of statistical techniques to mitigate any mismatches (e.g. difference-in-differencing). A number of studies use more than one approach, which also complicates classification. We then seek to refer to the more accurate method in the table.
Aspects of control group classification: Techniques for achieving a close match between the control group and treatment group include selecting control areas through propensity scoring, using areas that applied for but did not receive zone status, and using near neighbours. However, use of near neighbours as controls can contaminate the controls through spillovers.
Aspects of treatment group classification: The treatment group geographical areas are classed as exact if they exclude any parts of census tracts, ZIP codes, etc., that are not in the zone (even if not all the zone area is included), the time periods are classed as exact if the treatment data exclude any years outside of zone lifetimes (even if excluding some years in which the zone programme was applied), and the sector match is classed as exact if the data cover all the types of establishments treated (for example, they are not limited to manufacturing when other sectors are affected by the treatment).
Further detail on the methods used by each study is given in Table 4.
Employment impacts
Several evaluations of US state and federal interventions found no impact on local employment levels, one found a negative employment impact (Lambert and Coomes, 2001), and one found mixed results (Lynch and Zax, 2011). In contrast, several evaluations found substantial employment benefits. PACEC (1995) found that UK Mark 1 enterprise zones generated a near three-fold increase in local employment levels over 10 years. Two US federal empowerment zone evaluations put the policy-generated increase in local employment at 34% (Ham et al., 2011) and 15% (Busso et al., 2013). Among US state programme evaluations, policy was found to have increased local employment by more than one-third in Indiana (Rubin and Wilder, 1989), by an average of 10% across 17 states (Erickson and Friedman, 1990a, 1990b, 1991) and by 10% in Texas (Freedman, 2012). In France, Rathelot and Sillard (2008) found that zones had stimulated a local employment increase of approximately 15%, and Mayer et al. (2017) found a local employment increase of 24%. In between those evaluations showing substantial employment impacts and those estimating no benefits, there are several studies that found benefits that were relatively modest in scale. One US federal empowerment zone evaluation found an increase of only 130 jobs (Hanson and Rohlin, 2011, 2013), another found a modal increase across census tracts of approximately 13 jobs (Rich and Stoker, 2010), an evaluation of the Colorado state programme found an employment increase of 4% (Billings, 2009) and an evaluation of the California state programme found an employment increase in the order of 5%. In France, Givord et al. (2013) found increases of between 3 and 12 percentage points in employment and hours worked on zones.
Unemployment impacts
The majority of the studies that investigated impacts on local unemployment found benefits, although the precise measures varied. Ham et al. (2011) found that federal empowerment zones reduced the zone unemployment rate by an average of 9 percentage points and that a range of state enterprise zone programmes reduced the zone unemployment rate by an average of 1.6 percentage points. Sridhar (2000) found that one state programme had reduced local unemployment by 2.9 percentage points. On other measures, Papke (1994) found that a US state programme had reduced numbers of local unemployed people by 19%, Gobillon et al. (2010) found that French zones increased the exit rate from unemployment into a job by 3% per semester for local residents, and Rich and Stoker (2010) found that US federal empowerment zones reduced unemployment in one-half of the cities they evaluated. On the other hand, Oakley and Tsao (2006) found that US empowerment zones had no impact on local unemployment while Rogers and Tao (2004) detected no statistically significant impact of Florida small city zones on the unemployed-to-population ratio.
Are enterprise zones cost effective?
Although many evaluations found employment benefits, only ten compared the benefits with costs so as to permit some assessment of whether the policy could be considered cost effective. The majority of these found public costs per job created that might be considered to be very broadly in line with results achieved by similar interventions such as UK regional policy or US job subsidies. Five found the cost per job created below approximately USD 8000 per annum in 2016 prices (O’Keefe, 2004; PACEC, 1987, 1995; Rubin, 1990; Rubin and Wilder, 1989). Three found a cost per job created of between approximately USD 8000 and USD 20000 per annum in 2016 prices (Busso et al., 2013; Freedman, 2012; Papke, 1993). Erickson and Friedman (1990a, 1990b, 1991) and Rubin (1990) both concluded that enterprise zone policy had a negative cost per job once additional tax revenues generated had been taken into account. On the other hand, Rathelot and Sillard (2008) and Hanson and Rohlin (2011) estimated very high costs per job created, while of course several evaluations found no employment benefits that could be weighed against costs incurred.
What factors influence the employment impacts of enterprise zones?
Although in a few cases evaluations have produced different findings for essentially the same zone programmes in the same places and at the same times, the various evaluation studies are generally associated with different programmes and different contexts. Indeed there has been a richness of policy experimentation that might offer important insights in how to strengthen enterprise zone policy design by clarifying how different policy designs and contexts interact with processes affecting local employment outcomes, such as those suggested in Figure 1. Regrettably, few evaluations have systematically investigated these potential influences, but several evaluations offer useful indications that certain processes highlighted in the figure merit more evaluation attention.
Capital–labour substitution
The extent to which zone employment generation is impeded by capital–labour substitution in existing zone firms and high capital intensity in new-to-zone firms could vary with factors such as the relative value of capital and labour subsidies in zone packages, whether or not subsidies are conditioned on recruitment or capital investment and the relative importance within zones of industries with high capital–labour substitutability. Certain studies offer insights. Papke (1993, 1994) found that a capital-weighted subsidy resulted in increased employment as well as capital use. Greenbaum and Engberg (2004) and Bondonio and Greenbaum (2007) found that increased capital use by incumbent firms did not explain the absence of employment generation across the range of zone programmes they studied. On the other hand, Lynch and Zax (2011) argued that greater capital–labour substitution among establishments on urban zones might explain why rural zones had generated employment increase while urban zones did not, and could have been related to lower rural wage rates.
Labour and wage elasticity
If labour supply is constrained, increased employment demand generated by zone intervention might have much stronger impacts on wage rate growth than employment growth. The evidence from the evaluations is not very clear on how far this is an issue. There are few studies showing that an increase in wage rates has reduced employment growth, perhaps reflecting a genuine targeting of zones on areas with labour surplus. For example, O’Keefe (2004), Givord et al. (2013) and Mayer et al., (2017) all found that the zone employment growth that occurred was in situations where zone wage rates remained stable overall. Indeed, the latter authors found that the wage rates of non-low-wage workers fell, reflecting reduced relative demand for these workers. Other studies found that zone wage rates and employment volumes moved hand-in-hand (Busso et al., 2013; Ham et al., 2011) or did not move at all (Oakley and Tsao, 2006). Greenbaum and Engberg (2004) and Bondonio and Greenbaum (2007) found that zones reduced average wages (possibly due to requirements in some states that new hires are zone residents) but still did not increase employment.
Capitalisation of subsidies
One of the processes that might explain why enterprise zones sometimes do not create employment is a potential capitalisation of enterprise zone subsidies by property investors, developers and landowners. They may be able to react to the increased property demand by increasing the sale or rental prices of land and premises on zones, until the profitability of firms is equal on and off zones, leaving firms indifferent to an on-zone or off-zone location (Bond et al., 2013; Landers, 2006). The share of capitalisation could be influenced by factors such as the scale of availability of vacant local premises and the relative proportions of tenants and owner-occupiers on zones. The evaluations provide some evidence of capitalisation. PACEC (1995) found an accrual of subsidy values to landlords through rental appreciation of between 20% and 50% on the majority of UK Mark 1 zones. The rate was highest in tight property markets and fell towards the end of the zone lifetimes. Similarly, Hanson (2009) found that US empowerment zones had a substantial positive impact on median property values, which increased by over USD 100000. On the other hand, Boarnet and Bogart (1996) found that New Jersey enterprise zones did not affect property values.
Distribution of job gains
The share of new zone jobs going to in-commuters, new residents and people who were formerly inactive in the labour market rather than long-term unemployed residents could vary with factors such as the size of zones relative to their travel-to-work areas and whether or not the incentives are tied to hiring long-term unemployed residents. Some evaluations found that quite high proportions of jobs went to zone residents and the unemployed. On Mark 1 UK zones, approximately 90% of non-managerial/professional recruits were local residents and approximately 34% of recruits were previously unemployed (PACEC, 1995). Erickson and Friedman (1990a, 1990b, 1991) estimated that approximately 61% of jobs went to residents and approximately 48% to the unemployed on US state zones. On Texas zones, workplace employment growth only slightly exceeded resident employment growth (Freedman, 2012). 14 On the other hand, Busso et al. (2013) found that one-half of new jobs on US urban empowerment zones went to commuters and Papke (1993) found that only 15% of jobs created by Indiana zones went to zone residents.
Displacement of activity from outside of zones
Relocation or displacement of economic activity onto zones that would otherwise go elsewhere could be expected to offset the job creation benefits of zone policies, at least in so far as the activity is displaced from other high-unemployment areas. The degree of displacement could be affected by factors such as the distance of zones from other distressed areas and whether or not zone incentives are available for relocations. There is evidence from some of the evaluations that displacement can be a significant problem. By mid-lifetime on the UK Mark 1 zones, approximately 25% of new jobs had been displaced from other high-unemployment areas through establishment relocations; a further 31% of jobs were in inward investors that had chosen enterprise zones over alternative locations (which could include other high-unemployment areas) (PACEC, 1987). At the end of the UK Mark 1 zone lifetimes, the net job loss to the areas surrounding the zones was estimated at 51% of the jobs created within the zones (PACEC, 1995). Hanson and Rohlin (2011, 2013) found even larger displacement onto US urban empowerment zones from neighbouring and similar areas, which nearly completely offset the employment benefits generated within the zones. In France, Mayer et al. (2017) found that all zone employment growth was the result of relocations or diversion of new establishment creations from the rest of the municipality hosting a zone; that is, the policy generated no additional activity for municipalities hosting zones overall. Similarly, Givord et al. (2013) found negative spillovers from French zones on establishment stocks in the 300-metre rings surrounding zones, which nearly fully counterbalanced the growth in the on-zone establishment stock. On the other hand, Rathelot and Sillard (2008) and Gobillon et al. (2010) did not find important displacement effects on neighbouring municipalities from French urban zones. Furthermore, various US state enterprise zone policy evaluations found no displacement from other local areas (Freedman, 2012; Greenbaum and Engberg, 2004; Neumark and Kolko, 2010), while Ham et al. (2011) found that the limited local spillovers that did exist were positive.
Sites and premises availability
The ability of certain enterprise zones to offer large volumes of available sites and premises to accommodate new and expanded business activity could have an important influence on the scale of employment impacts. Much of the success of the UK Mark 1 zones was attributed to an increase of 60% in the floor space available on the zones between their designation and the mid-point of their lifetimes. This was the result of the presence of large empty and redundant sites within designated zone areas combined with public investments in removal of dereliction and landscaping, streamlining of planning procedures, incentives for property investors, and subsidies to premises’ occupants (PACEC, 1987). Enterprise zone job creation effects could be more limited in places where land and premises are more constrained.
What is the influence of different zone programme designs and zone contexts?
The above discussion points to a number of potentially important processes affecting the local employment effects of enterprise zone policy that could be influenced by various aspects of zone programme designs and zone contexts. Mayneris and Py (2014) make a similar argument, focusing on the possible influences of initial conditions of zones in terms of density of existing firms and accessibility to workers and consumers, zone exposure to industries where firm relocation costs are lower, such as professional services, and the amount and range of tax incentives offered by the policy. Table 3 summarises some key variations across the evaluations in the nature of the zone programme designs and zone contexts evaluated. It shows that there are a number of variations in the focus of the evaluations that might be exploited for comparative analysis. These variations include whether or not the evaluated programmes made zone incentives conditional on new hiring, designated the zones solely on grounds of economic distress, placed zones solely in urban locations, and operated in periods of strong or weak national labour market performance.
Variations in key features of programme designs and contexts assessed by different evaluations.
Note: The evaluation is reported as including employment-tying if any incentives in the evaluated programmes were conditional on new recruitment or another positive employment outcome. Evaluations were characterised as focusing on distress if areas were principally selected for designation because of high unemployment and poverty. The national labour market tendency is characterised as healthy if the national unemployment rate reduced by at least two percentage points over the period of the study; otherwise it is characterised as weak. Evaluations are characterised as urban-only if all the evaluated zones were in urban areas and mixed if they included both urban and rural zones.
Unfortunately, there has been relatively little deliberate comparative assessment, within individual evaluations, of the influences of different zone programme designs and different zone intervention contexts on local employment impacts, although some evaluations have done this. Furthermore, the data reported in the individual evaluations do not lend themselves to a formal meta-analysis or meta-regression on how such variations affect employment impacts because of numerous differences in the nature and definitions of the explanatory and response variables that have been used. We undertook bivariate analyses for this paper, but they showed no clear relationships between whether or not the zones generated employment benefits and variations in zone incentive tying, levels of distress, urban–rural context or national labour market performance.
On the other hand, there are some indications from specific evaluations that some of these aspects of zone programme design and context may be influencing employment impacts. One of the major criticisms of enterprise zone policy is that it may offer important windfall gains to pre-existing businesses on zones if they are able to access employment or capital subsidies intended to encourage growth without changing their behaviour (Bartik, 2001; Bartik and Eberts, 2012; Bond et al., 2013; Neumark and Grijalva, 2013; Neumark and Simpson, 2014). For example, Neumark and Kolko (2010) highlight a situation involving Californian zones, whereby firms could retroactively claim hiring tax credits up to four years after hiring took place, implying the possibility of significant windfalls. They found that if zone managers concentrated on marketing retroactive credits to existing firms their zones created fewer jobs. Givord et al. (2013) also illustrate the windfall issue, showing that there was no impact on the economic activity of incumbent firms in French zones although they were eligible for most of the tax incentives by their simple presence in the zone. Programme designs that make subsidies conditional on new hiring might reduce this windfall effect. However, one of the few studies that compared programmes tying incentives to job creation or capital investment with those that did not found that conditioning of incentives made no difference to aggregate zone employment creation (Bondonio and Engberg, 2000).
One of the issues that has been subject to significant comparative attention, at least in a minority of evaluations, is the influence of geographical context on zone employment impacts. Erickson and Friedman (1990b) found that zones were more successful if they were in ‘retrievable’ areas rather than severely economically distressed areas. Moore (2003) found that rural zones in California were more likely to grow than urban zones. PACEC (1995) found that employment growth was greatest in accessible suburban areas, and to a lesser extent in rural areas, and performance was weakest in the most distressed urban core areas. Lynch and Zax (2011) found that while urban zones in Colorado had no positive employment impacts, there were positive impacts in rural zones, possibly reflecting the availability of an additional complementary subsidy there and a lower probability of capital–labour substitution. Mayer et al. (2017) found that policy impact was stronger in zones with larger establishment densities, suggesting that policy impact may also be influenced by agglomeration effects.
None of the evaluations included much discussion of the extent to which zone employment effects vary between periods of strong and weak overall national labour market performance, although this might be expected to be a significant factor in zone performance. On the other hand, a number of other potentially important zone design and context features are highlighted by certain evaluations. Notably, the positive employment impacts of zones might be greater: in areas with more capable local development agencies (Rich and Stoker, 2010) or where an area development plan was required (Bondonio and Greenbaum, 2007); in programmes that offer a greater value or wider range of incentives (Beck, 2001; Erickson and Friedman, 1990b) and complementary job training and community development support (Beck, 2001); in zones with smaller land areas (Bondonio and Greenbaum, 2007; Erickson and Friedman, 1990b); and in zones with lower shares of manufacturing, linked to greater capital–labour substitution opportunities in manufacturing than in services (Neumark and Kolko, 2010).
Given the relatively disparate nature of the current evidence, more studies are needed that examine and report on the potential influences on zone success, and which of them are important and in which ways. In particular, more systematic comparative evaluations of the impact of variations in programme designs and zone contexts would be very valuable in helping inform future enterprise zone policy design.
Improving data quality
Table 4 summarises key methodological features of the reviewed evaluations. It distinguishes between a few (generally older) studies that estimated impact by surveying managers of zone-based firms, and a vast majority of econometric or shift-share analyses typically comparing employment changes between treatment and control areas. It provides brief information on the methodologies applied. A potential weakness of the beneficiary survey methodologies is that their self-assessment impact estimates may not be reliable (Greene, 2008). Less well recognised is a potential weakness with many of the econometric studies, which, as indicated in Table 4, frequently use treatment and control data that do not fully match the policy-on and policy-off situations required for modelling.
Summary of key methodological and data features of enterprise zone evaluation studies.
There are three main issues. First, approximately one-half of the econometric evaluations used treatment data that did not entirely match the zone geography, generally by approximating zones with larger units that included some non-zone territory. Further, approximately one-third used control area data that included some zone territory. These imprecisions could affect the accuracy of results, particularly if zones have important spatial spillovers. Indeed, Mayneris and Py (2014) argue that poor delineation of zone boundaries together with endogeneity issues involving time-varying unobservable factors that are not picked up by difference-in-difference and propensity score matching can explain part of the conflicting results of enterprise zone evaluations to date. To help address the problems, some recent studies have used precise GIS coding to attribute firms to zone and non-zone areas, whilst US federal empowerment zone boundaries were drawn up to match with census areas. Second, nearly one-half of the econometric studies used data that did not match the time periods of treatment, generally by including some non-treatment years and excluding some treatment years. Moreover, several studies examined impacts only a short time (e.g. 1 to 3 years) after zone establishment, although zones may build up jobs gradually, while very few studies took a sufficiently long view to assess whether zones have durable impacts after de-designation. Third, several evaluations used only data for manufacturing, although zones also typically support service sector firms and there may be differences in the ways that services establishments and manufacturing establishments respond to incentives, particularly concerning capital–labour substitution. It is also worth recognising that other area-based policy interventions often operate in areas targeted by enterprise zone programmes and that enterprise zone evaluations have not always sought to disentangle enterprise zone impacts from those of the other interventions. 15
As well as showing the estimated employment impacts of the different evaluations, Table 2 also presented a very simple characterisation of the closeness of fit of the control and treatment data used in each study. It highlights several areas in which the data used in the evaluations have not fully matched the treatment or non-treatment situations. Only around five of the evaluations were able to apply fully matching data for both the treatment and controls. 16 Only 20 of the 34 studies reviewed here used control group areas that were both a close match in economic conditions to the treatment areas and unaffected by potential local spillovers. 17 It is important to address these data issues in order to increase confidence in enterprise zone evaluation results and the policy conclusions that can be drawn from them.
Conclusions
The aggregate evaluation evidence is currently divided on whether or not enterprise zone policy is an effective and efficient tool for local employment development. While problems with the quality of data used for some evaluations may be an issue, it is likely that the major explanation for discrepancies in findings across evaluations is to do with differences in the programme designs and operating contexts of the zones they have evaluated. It is therefore a priority to increase understanding of the influence of enterprise zone programme designs and application contexts. Building the evidence required implies developing more theoretically driven studies that seek to identify the range of factors and channels that influence the degree of enterprise zone policy success in local employment development and how they could be affected by enterprise zone policy designs and contexts. More comparative evaluations would also help, seeking to cover multiple programme designs and contexts in the same studies. At the same time, confidence in evaluation results could be increased by efforts to improve the match between the treatment and control data and the geographies and timings of the zone interventions. A boosted enterprise zone evaluation agenda of this kind would help governments make more informed decisions about enterprise zone policy and other place-based tax incentive driven interventions for local employment development.
Footnotes
Acknowledgements
We would like to acknowledge the great support and encouragement provided to the authors by the late Barry Moore, Fellow of Downing College and Emeritus Reader in Economics at the University of Cambridge, who offered comments and suggestions on early versions of this paper and worked with us and advised on many other projects.
Disclaimer
This paper is published under the responsibility of the authors. The contribution of Jonathan Potter is in his personal capacity and the opinions expressed and arguments employed herein do not necessarily reflect the official views of the Organisation for Economic Co-operation and Development or its member countries.
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
