Objectivity and falsehood: Assessing measures of positional influence with members of David Cameron’s cabinets

This paper analyses the distribution of power among ministers during David Cameron’s premiership. More specifically, it reports both the application of Dunleavy’s measures of positional influence to successive lists of cabinet committees and our efforts to validate them by drawing on insider feedback. It charts how the cabinet-committee system changed between 2010 and 2016, and interprets successive rankings of ministerial influence. It further investigates the nature of power in Cameron’s governments by engaging with a number of former ministers’ responses to our measures. Those we spoke to were generally sceptical of the importance of cabinet committees and especially of our attempts to derive measures of ministerial influence from them. Overall, our findings emphasise the dangers of attributing too much importance to formal structures and instead draw attention to how contemporary core-executive politics are shaped by informal networks and structures.


Introduction
Empirical research rarely goes according to plan. Evidence is often only partly consistent with expectations, and sometimes it entirely contradicts them. This paper reports findings that fall into the second category. We set out hoping to validate Dunleavy's (1995Dunleavy's ( , 2003 'positional-influence' measures, a way of scoring ministers' intra-executive power on the basis of cabinet-committee memberships, by speaking to former ministers and section discusses the implications of our findings, both in terms of measuring power in Britain's core executive and the wider analytical value of studying cabinet committees.

Power and influence in cabinet committees
The starting point for our research was Dunleavy's (1995Dunleavy's ( , 2003 innovative framework for analysing ministers' influence in government on the basis of their memberships of cabinet committees. Cabinet committees have long been a feature of British government, bringing together smaller groups of ministers to prepare or formally approve policy (Burch and Holliday, 1996;Catterall and Brady, 1998;Gordon Walker, 1972;Hennessy, 1986). Yet, their work was shrouded in official secrecy until 1992, when John Major established the practice of publishing their names, remits and memberships. Dunleavy (1995: 303-304) used this information to assess systematically the distribution of influence over collective decision-making within the committee system. The underlying logic was summarised in a follow-up study of power in Tony Blair's government: 'Policy making inside government is like a lottery process in one small respect -you have to be in it to win it' (Dunleavy, 2003: 343).
Deriving measures of ministerial influence from cabinet committees was a two-step affair. The first step was to identify the relative importance of every committee in the system. To do this, Dunleavy (1995: 306) calculated a 'weighted influence score' for each committee, which reflected its status as either a full committee or a sub-committee (full committees were assumed to carry twice the weighted influence of sub-committees), and the proportion of its members who were full cabinet ministers (the higher the proportion, the more important the committee). The calculation was based on a simple formula: influence = 100 * S * (C/N), where S was the official status of a committee (full committees scored 1, and sub-committees scored 0.5), C was the number of cabinet-level members and N was the total membership. The second step was to divide this score among the committee's members. Every member received an equal share except for the chair, who received a double share (Dunleavy, 1995: 307). 1 Individual ministers' shares of all weighted scores were then aggregated, creating a single composite score for every minister that could be expressed as a percentage of the sum of all ministers' scores across all committees.
Dunleavy's initial study, which focused on Major's government in 1992, showed the prime minister to have the highest share of positional influence. The next most influential ministers were the foreign secretary, defence secretary, and chancellor of the exchequer (Dunleavy, 1995: 308-309). His follow-up study of Tony Blair's government in 2001 revealed a decline in the prime minister's overall share of positional influence in the cabinet-committee system (Dunleavy, 2003). Meanwhile, a later study of the 2010 coalition government, using the same method, suggested a further decline in the prime minister's influence (Royal Holloway Group PR3710, 2012). It also suggested the Liberal Democrats enjoyed disproportionately greater influence than their ministerial representation in the government might have suggested.
Like many innovative approaches, Dunleavy's has its detractors. One criticism concerns its imprecise conceptualisation of influence (James, 1999: 63). Ministers might have broad strategic influence, or they might exert influence over very specific decisions. Both can be important, but they are very different things.
A second criticism concerns the use of committee memberships to measure ministerial influence (Catterall and Brady, 1998: 74). There has always been variation in how committees function in practice. Under Blair, for example, there was a general downgrading in their importance as 'sofa government' replaced cabinet government. Key decisions were often made in informal gatherings, while committees were characterised as 'hollow shells' (Hazell and Yong, 2012: 50). More generally, committees have tended to function as deliberative decision-making bodies only when prime ministers have wanted them to (Catterall and Brady, 1998: 76). Power and influence, in other words, are exogenous to the cabinet-committee system. Using committees to measure influence confuses cause and effect.
In fairness, Dunleavy was open about the measures' limitations, as well as the assumptions on which they were based. He recognised that there were other decision arenas in government and a great deal could be agreed in advance in discussions between key departments or in bilateral meetings between spending departments and the Treasury or Downing Street; but as he also correctly noted, 'at some stage all the threads of these diverse forms of discussions have to run together in a Cabinet Committee decision' (Dunleavy, 2003: 344). Even under Blair, committees continued to ratify decisions and confer collective authority upon them, structure inter-departmental relations and provide a mechanism for departments to clear policies, and even occasionally allow ministers to meet, share information and talk politics. Dunleavy was also clear, as he put it, that the scores 'should not be fetishised, nor should any fine or precise significance be attached to them'. Rather, they were a 'heuristic' and served as 'pegs which help us to think further about the ways cabinet committees and ministerial influence over decision making can be patterned' (Dunleavy, 1995: 319-320). In this respect, the scores had the great virtue of reliability: they opened up the possibility for undertaking systematic comparisons over time.

Structure and influence in Cameron's committee system
Any analysis of cabinet committees and ministerial influence in David Cameron's governments must begin by recognising that his was a premiership of two halves. Between 2010 and 2015, he headed a Conservative-Liberal Democrat coalition. From the 2015 general election until just after the June 2016 Brexit referendum, he led a single-party Conservative government. These different circumstances placed different demands on the cabinet-committee system and affected its organisation and structure.
Before he became prime minister, Cameron had talked about wanting to restore 'cabinet government' and the institutions of collective decision-making (Clarke, 2016: 460). Following the outcome of the 2010 general election, he had an added incentive to do so. For Cameron and Liberal Democrat deputy prime minister Nick Clegg, cabinet committees were an obvious means to manage inter-party relations and 'coalitionise' policy (d 'Ancona, 2013: 37;Dorey and Garnett, 2016: 37-38;Hazell and Yong, 2012: 53-55). Cheered on by civil servants, who wished to restore more orderly decision-making (Hazell and Yong, 2012: 51), the Coalition Agreement for Stability and Reform committed the new government to making 'full use' of the committee system to deliver collective responsibility (Cabinet Office, 2010: 3).
The result was a slimmed-down committee system, first unveiled in May 2010 (see Figure 1). It comprised three types of committee. The first and most important of these were the standing policy committees, which included the National Security Council (NSC), the Home Affairs Committee, the Economic Affairs Committee, the Social Justice Committee and the European Affairs Committee. These were permanent features of the committee system, had wide remits and coordinated major areas of policy. The second type was the policy sub-committee, usually a smaller body with a narrower remit that nominally reported to one of the standing committees, such as the NSC's Nuclear Deterrence and Security Sub-Committee.
The third type was what might be called 'staff' committees, bodies that were created to help manage government business. They included the Parliamentary Business and Legislation Committee and the Coalition Committee, a body chaired jointly by Cameron and Clegg that was intended to act as a final court of appeal for inter-party disputes in other committees. They also included at this stage the Coalition Operation and Strategic Planning Group, an entity that was explicitly not a cabinet committee but which was intended to support the Coalition Committee.
This initial configuration did not last. Some bodies were disbanded, and additional committees and sub-committees were established, usually in response to the changing agenda and press of events. In late 2012, for example, a Scotland Committee was established to prepare the government's strategy for the planned Scottish independence referendum, while a Flooding Committee was established in early 2014 in response to that year's winter floods. After the 2015 general election, Cameron re-oriented the committee system to meet the demands of single-party government (see Figure 2). He retained the major standing policy committees but introduced several new committees, most notably the Europe Committee to prepare for the planned EU referendum. He also introduced an entirely new class of body, implementation task forces. These were not policy-making committees but ministerial groups responsible for monitoring and driving forward key cross-cutting policies (Letwin, 2018: 233-235).
Taking a step back, Figure 3 draws on all the lists of committees published between May 2010 and April 2016 to chart how the committee system changed across Cameron's premiership. It shows that the total number of committees proliferated after 2010. By June 2013, the mid-point of Cameron's premiership, there were 28. The total number of committees also proliferated after the 2015 general election. The return to single-party government saw an initial cull in the number of committees and sub-committees, as well as the advent of a number of implementation task forces. By the end of Cameron's premiership, the number of committees, sub-committees and task forces had all increased, taking the total number of all types to 31.
We now turn to our application of Dunleavy's measures to Cameron's governments. We made three minor adjustments to the measures in order to accommodate developments in the composition and organisation of cabinet committees. First, when calculating a 'weighted influence score' for each committee, we counted as cabinet ministers all those who 'attended cabinet', as well as full members. This category of ministers has grown in recent years as prime ministers have sought to confer 'cabinet status' more widely. 2 Second, we assumed that implementation taskforces had the same basic importance as sub-committees, that is, half the weight of full committees on the basis of their narrower remits. 3 Third, while chairs and co-chairs alike earned a double share of each committee's weighted score, deputy chairs and co-deputy chairs earned a share and a half. The role of deputy chair was central to the coalition government: all committees had a chair from one party and a deputy chair from the other, each of whom could escalate decisions to the Coalition Committee if need be. This adjustment to Dunleavy's measures recognised their importance. Table 1 reports the resulting standardised scores of the 20 most influential ministers at the beginning of Cameron's premiership in May 2010 and after three extensive cabinet reshuffles: in October 2012, December 2014and July 2015 The chancellor of the exchequer, George Osborne, accrued the highest share of influence at all points between the 2010 and 2015 general elections, and the second highest share in 2015. Another notable high-scorer throughout Cameron's premiership was Oliver Letwin, first as a minister of state in the Cabinet Office, and later as chancellor of the Duchy of Lancaster.
Cameron, meanwhile, never ranked higher than third, and had only the fifth highest score in 2012. During the period of coalition government, Nick Clegg was initially placed second, before moving further down the rankings. In 2012, his score was lower than that   Dunleavy's (1995: 319) counsel about not attaching 'precise significance' to the measures, the scores seem to have some value. They highlight, for instance, the strategic influence of Osborne throughout the whole of Cameron's premiership, and also the prominence of Letwin, the government's policy-fixer in chief (Rentoul, 2015). A behind-the-scenes minister, it was Letwin's job to ensure that decisions were consistent with Cameron's preferences. From a Liberal Democrat perspective during the period of coalition government, the scores also highlight the reputed influence of Danny Alexander . Likewise, the scores accord with another former leader's more limited standing in the government. Iain Duncan Smith was appointed as work and pensions secretary in May 2010, but was required to share the task of delivering welfare reform with Osborne. Osborne and Cameron almost governed as duumvirate and reportedly did not rate Duncan Smith all that highly (d 'Ancona, 2013: 86-92). The latter's measured influence placed him 13th, 18th, 18th and 9th, respectively.

Validity, value and realist interviews
The scores and overall rankings we report undoubtedly bear some resemblance to previous accounts of Cameron's government. In this sense, they appear to have some degree of 'face validity' (Bryman, 2016: 159). But how confident can we be that they adequately capture the concept of positional influence? After all, the scores' practical value, even as heuristic 'pegs' for thinking about ministers' intra-executive power, ultimately depend on their measurement validity (Adcock and Collier, 2001). If the scores end up providing a wholly misleading representation of who has influence, there is little point in employing them. Alternatively, if the goal is simply to produce a set of measures that serve as a starting point for thinking about intra-executive power, then simpler indicators, for instance, the number of committees that ministers sit on, may serve just as well. Either way, the validity of the measures needs to be established.
Following Adcock and Collier (2001: 531), measurement is valid when scores derived from indicators can be meaningfully interpreted in relation to a systematised concept. For our purposes, the key question is how far the scores can be interpreted meaningfully in terms of ministers' influence in the committee system. In an ideal world, we might pursue a strategy of what they term 'convergent validation' (Adcock and Collier, 2001: 540-542) by relating the scores to alternative indicators of influence, such as the number of new policies successfully proposed by each minister or successfully vetoed. The goal, of course, would be to infer the number of decisions made in line with ministers' preferences. In practice, however, there are no readily available indicators. Because of official secrecy, we know very little even about how frequently committees meet, who actually attends them, how many papers are circulated or what positions ministers take on each item. 5 Instead we pursue a strategy of 'content validation' (Adcock and Collier, 2001: 538-540) and seek to establish whether the positional-influence measures fully capture the nature of the cabinet-committee system during Cameron's premiership. To this end, we sought feedback on the scores and measures from those who had expert knowledge of Cameron's governments: former cabinet ministers and officials. We did so through a combination of face-to-face interviews and written correspondence. Our approach was thus consistent with what Pawson and Tilley (1997: 155) call 'realistic interviews': we used the respondents as 'co-researchers' to help us confirm, falsify or refine our measures, not as subjects of study in their own right (see also James, 2018).
More specifically, we sought feedback on three particular aspects of Dunleavy's measures: first, the assumptions surrounding the relative importance of committees and subcommittees and the plausibility of their weighted influence scores; second, the assumptions surrounding the division of committees' influence scores, in particular the nominal equality of members and the special positions enjoyed by chairs and deputy chairs; and finally, the plausibility of the resulting scores.
We approached a number of individuals with firsthand experience of cabinet-level decision making between 2010 and 2016. In the event, we conducted four anonymous semi-structured interviews. 6 Three of those we spoke to agreed to participate in part because they were sympathetic to the basic premise of developing measures. In all cases, we discussed at length both the assumptions underpinning Dunleavy's measures and the resulting scores and rankings as reported in Table 1. Because we had difficulty in convincing more former ministers to speak to us, we solicited additional feedback by correspondence. Altogether, we received written feedback from nine former cabinet ministers (out of 32 individuals contacted). They included eight Conservatives and one Liberal Democrat. Their anonymised comments constitute an invaluable source of data for assessing how insiders view influence in the cabinet-committee system and the validity of the positional-influence measures.

Committee influence scores
The first aspect of Dunleavy's measures on which we sought feedback related to the assumptions surrounding the calculation of committees' weighted influence scores. Dunleavy assumed, not unreasonably, that committees varied in importance, partly on the basis of whether they were full committees or sub-committees and partly on the proportion of members who were of cabinet rank. Did former ministers agree?
In one sense, there was some support for the underlying rationale: there was unanimous agreement that committees varied in importance. As one respondent wrote, 'all committees are not equal', and went on to point out that the Social Justice Committee's Child Poverty Sub-Committee was obviously inferior to the NSC, which Cameron used to develop his thinking on foreign and security policy (correspondent, 5). Another told us that the Parliamentary Business and Legislation Committee, which considered proposed bills and decided on the legislative timetable, had more '"active" influence than, perhaps, a policy committee ' (correspondent, 8). But there was no support for the idea that the importance of committees could be calculated consistently on the basis of their membership or formal status. As one former minister told us, a sub-committee did not automatically carry half the weight of a full committee: this approach was 'falsely precise' (interviewee, 4). Some sub-committees were more important than full committees, notably the NSC sub-committees, which were 'essentially the NSC minus one or two people' (interviewee, 2). Similarly, another former minister could not recall ever convening a meeting of the sub-committee he chaired; its business was always covered in the main committee's meetings (interviewee, 1).
Two clear points emerged from the feedback: there was a clear pecking order of committees, and different committees were important in different ways. For instance, the NSC was consistently identified as the most important deliberative body. As one former minister told us, 'there were genuine discussions, and the weight of opinion [in meetings] mattered, especially on issues that the prime minister was less certain about' (interviewee, 2; see also Clarke, 2016: 465). The Home Affairs Committee too was reckoned by interviewees to have been 'very important' for discussion (interviewee, 1), at least during the early stages of the coalition government when it served as a key venue for 'throat-clearing' and managing inter-party differences (interviewee, 4; see also Willetts, 2015). It most important role, however -which it performed exclusively after 2015 -was to enable departments to clear policies via correspondence through the 'write around'. Meanwhile, some committees focused 'on matters of implementation rather than policy making' (interviewee, 3) or 'operational' matters, monitoring decisions taken elsewhere (interviewee, 4). It was not just the post-2015 implementation task forces that performed this role.
There were also limits to the importance of formal structures. On paper, the Coalition Committee was arguably the most important body between 2010 and 2015 and served as a capstone to the committee system. But it met on only a few occasions, and its work was almost entirely superseded by the Quad (see d 'Ancona, 2013: 36;Hazell and Yong, 2012: 53). Indeed, one respondent was 'extremely cautious about using memberships of Cabinet Committees as any kind of proxy for "power"', because 'real decisions' were generally made informally (correspondent, 1). Similarly, another former minister insisted that committees were 'vastly over-rated as decision-making bodies', and their work was generally 'formal and routine' (correspondent, 7).
A number of our respondents also highlighted cases where committees were important not as institutions of collective decision-making but as instruments of individual ministerial control. For example, the Economic Affairs Committee chaired by George Osborne was important, not because it met and discussed policy -it did not -but because it was used by the chancellor to control policy in this area (interviewee, 2). During the period of coalition, the Banking Reform Committee was also important for a while, again not because it met and discussed policy -according to one of its principal members, it did not hold a single meeting (correspondent, 7) -but because it enabled Osborne to develop an approach to the subject in conjunction with Vince Cable (interviewee, 4).
Another point to emerge from the feedback we received was that context mattered enormously. As one former minister put it, some committees were 'more important at some times than others [and] even each committee fluctuates', making it 'hard to meaningfully quantify', and 'probably inadvisable to do so' (correspondent, 5). Some committees undoubtedly carried more weight in the early part of the coalition government precisely because there was a coalition. The Home Affairs Committee during this period was 'a powerful and important decision-making committee with real checks and balances', because it served as means of structuring inter-party discussion over a broad swathe of public policy (interviewee, 1). As the relationship between the two parties deteriorated, the committee's value diminished, and it 'came to be seen as a constraint by Conservatives and thus an object of dislike' (interviewee, 4). After 2015, the committee 'no longer mattered' (interviewee, 2).
The implications of this variety are clear: categorising a committee's influence without paying attention to what it actually does leads to measures that bear little resemblance to a committee's practical importance. To illustrate this point, in November 2013 three committees obtained the highest possible weighted score of 100: the Coalition Committee, the NSC and the Public Expenditure Committee. Yet, the first essentially existed on paper, and the last made no policy but existed simply 'to bash departments into submission at relevant moments in relevant spending rounds' (interviewee, 2). Only the NSC performed anything akin to a policy-making role. All three committees, however, had the same weight according to Dunleavy's measures.
An alternative indicator of committee importance that several respondents suggested was whether on or not a committee was chaired by the prime minister. In Dunleavy's original framework, the proportion of members of cabinet rank determined the weighted score of a committee or sub-committee. But while the presence of key ministers could well signal importance, prime ministerial participation was a virtual guarantee of it. Certainly, Cameron's presence on a committee usually indicated that it was likely to be an important forum, and attendance at committees was usually much greater when he took the chair. As one former minister said about the weighted scores for prime ministerial committees, 'I'd probably give a rocket boost to it for attendance of the PM, which I think hugely raises the stakes' (interviewee, 1).

Apportioning committee influence
The second aspect of Dunleavy's measures on which we sought feedback was how committees' weighted scores were subsequently divided. Did insiders agree that all members should automatically be given an equal share, and chairs and deputy chairs an extra share?
The answer was generally 'no'. Although chairs and deputy chairs were reckoned to have some additional influence (interviewee, 1), the role of committee chair was 'not a prism through which power was articulated'. Assuming they had twice the influence was 'bogus' (interviewee, 4). Instead, according to one former minister, the influence of chairs varies on 'a case by case basis' and depends on informal rules, in particular 'who has the ear of the PM, who has relations with who else' (interviewee, 2). He reckoned that the prime minister enjoyed '90 percent of influence' on the NSC, Nick Clegg enjoyed '50 percent' on the Home Affairs Committee and George Osborne '20 percent' on the Scotland Committee. At the same time, some chairs were more influential than others as a result of their approach to the role. While some chairs would do their homework, 'There are some who'd just look at the brief when they get in the room and make a complete dog's dinner of it' (interviewee, 3).
The same factors that affected the influence of chairs and deputy chairs on a committee also affected the relative influence of individual members. Some ministers were taken more seriously because of their office and who they were, others because of their close relationship with the prime minister, and yet others because of their standing in the party.
Again, some ministers could have greater influence because of their mastery, and acknowledged mastery, of policy. Oliver Letwin, for example, was known to be Cameron's agent in the committee system but he was also known for his expertise: in meetings, it was clear that he 'was the type of person who [had] thought about everything . . . and came up with some sensible ideas' (interviewee, 3). Many ministers, in contrast, were there to make up the numbers and 'might contribute absolutely nothing' (interviewee, 3). Some senior ministers never bothered to attend meetings.
At the same time, ministers differed in their willingness to speak out on areas outside of their immediate area of responsibility (Laws, 2016: 191). Theresa May (interviewee, 3) and Amber Rudd (interviewee, 2) were cited as ministers who tended to stick to their departmental briefs, whereas Michael Gove (interviewee 1), George Osborne (interviewee, 3) and Philip Hammond (interviewee, 2) were cited as ministers who ranged more widely. Attributing equal potential influence to every member of the same committee was deeply problematic.

The scores' accuracy
The final and perhaps most important aspect of Dunleavy's measures on which we sought feedback was their overall accuracy. Did insiders find the scores and rankings plausible?
In practice, not one of our respondents regarded the scores and rankings (see Table 1) as precise indicators of actual ministerial influence. One rejected their plausibility outright with a simple 'no' (correspondent, 4), and another with an equally simple 'not really' (correspondent, 8). Yet another former minister who examined the rankings from October 2012 said: 'No one in their right mind would recognise this list' (interviewee, 4). Some respondents qualified their rejection of the results. For one former minister, the scores were plausible to 'some (v. limited) extent' but also 'overly simplistic' (correspondent, 5). For another, the initial rankings in May 2010 seemed 'broadly sensible' at first glance, but he began to quibble various rankings upon closer inspection and came to the view that 'it doesn't look right' (interviewee, 1). Nor did longitudinal changes in the scores always make sense to our respondents. One minister who attended cabinet from 2010 to 2016 rejected the suggestion that Theresa May was more influential after 2015, even though her ranking went up from 13th in December 2014 to 3rd in July 2015 (interviewee, 2).
Insofar as the scores and rankings seemed plausible, it was usually because the more senior offices -the prime minister, the chancellor, the home secretary, the foreign secretary and the deputy prime minister during the coalition -were generally ranked towards the top. Beyond this, however, there were problems. The biggest problem for respondents was the relatively low ranking of the prime minister. As one interviewee told us, 'You need [the] prime minister and chancellor right at the top. Anything that doesn't have that, just doesn't get what's going on' (interviewee, 3). Another simply found it 'hilarious' that the prime minister never topped the rankings (interviewee, 2). Another former minister told us the rankings were 'not quite' plausible and revised those from May 2010 and October 2012 to indicate that the prime minister should be top (correspondent, 9). One former minister who sat in cabinet for most of Cameron's premiership observed bluntly: 'the more I think about it, the more convinced I am that this isn't 'research' quality' (correspondent, 5).
One clear point that emerged from both our interviews and written feedback was the importance of informal power structures and the measures' failure to account for these. During the coalition, the Quad was the most important forum for addressing inter-party disputes and driving the agenda. Then, and after, being close to Cameron and part of his inner team was what mattered most for shaping policy. In this respect, as one former minister told us, 'the top of government has striking similarities to the Tudor Court' (correspondent, 2). Another former minister expanded on this point and how court politics in turn shaped the dynamics of the cabinet-committee system: [T]he power structure is best conceived of as a court. Some places are held by elected politicians, some by peers, some by officials. All are courtiers. In every committee, for example, a decision is made by the PM or at least allowed to be made. There is a positive decision to allow it. The PM can look at minutes and if a decision is made that goes against what he wants, the decision can be re-run, or, if not, re-written . . . Court membership is what matters. (interviewee, 2) Needless to say, the measures neglected these factors, both in their assumptions and results.

Discussion
David Cameron's premiership began and ended in unusual circumstances. Like all prime ministers, he was able to shape the character and practice of collective decision-making (Heffernan, 2003;King, 1991). During his time in office, Cameron established a relatively small number of cabinet committees, certainly when compared to his immediate predecessors. Most committees coordinated, discussed or chased decisions made elsewhere. Only a few ever functioned as deliberative decision-making forums. Even during the period of coalition, when committees had been expected to play a bigger role, they tended to ratify and process policy decisions made in departments or by the inner Downing Street circle (see Clarke, 2016: 451;Clegg, 2016: 78-79;Laws, 2016: 509-510).
Cameron may have tolerated discussion and promoted collegiality, but he had no wish to revitalise Clement Attlee's style of government built around a powerful cabinet-committee system. Moreover, while Cameron took a leading role in the NSC, other ministers handled the formalities of the system's domestic work. George Osborne kept a tight grip on economic policy by effectively neutering the Economic Affairs Committee, while Nick Clegg and later Oliver Letwin managed the coordination of domestic policy through the Home Affairs Committee.
Where does all this leave Dunleavy's positional-influence measures? In one sense their value is clearly limited. Our respondents did not reckon the scores and rankings to be particularly accurate, while the measures omitted crucial informal factors that shaped ministers' capacity to influence decisions. Our respondents also said they overstated the importance of the committee system as a forum for decision-making. More generally, as one former minister put it, cabinet committees had 'no or vanishingly little connection to power' (interviewee, 2).
Of course, our respondents might simply have misunderstood the purpose of the measures. They might not have been thinking about influence in the specific and narrow context of the cabinet-committee system. They might even have underestimated the actual importance of committees. Set against this, however, is the certainty with which they rejected the scores. The weight of insider opinion was persuasive.
At the same time, the scores unintentionally demonstrated some utility as a heuristic for exploring intra-executive power dynamics, insofar as they facilitated discussions with those who had direct experience of the top of government. A number of our interviewees and respondents took the time and effort to engage with the measures and indicate who, in their opinion, should have received higher or lower scores. As a basic approach, such conversations can be extremely fruitful, especially when researchers are told that such and such a minister had very little influence, or so and so was actually very influential behind closed doors. Nevertheless, we suspect that such conversations could be prompted just as well by simpler measures, such as the number of committees that ministers chaired, or the number of committees on which they sat.
In general, our findings are probably best described as a series of cautionary tales about applying objective measures to something as concealed and dynamic as influence within government. In this respect, Converse's (1964: 206) doctrine 'that what is important to study cannot be measured and that what can be measured is not important to study' might have been written about power in the core executive.
If we wish to explore cabinet committees as institutions in their own right, published lists can only be a starting point. As those we spoke to made clear, there is enormous variation in the role, remit and importance of committees. This variation merits systematic empirical analysis using data that can only be gathered through in-depth elite interviews. Students of government still have much to do in terms of distinguishing between forms and functions, and developing appropriate categories.
Published lists of cabinet committees may also be useful as a starting point for exploring other aspects of government. As we have demonstrated, they can serve as a basis for engaging with ministers and officials and talking about influence. We also think they could be used to explore how individual ministers are networked with one another, as one of our respondents suggested (interviewee, 2). Published lists could even potentially be used as a basis for exploring the changing 'policy agenda' of the core executive (John et al., 2013). It is clear, simply from eyeballing successive lists of cabinet committees, that the system is responsive to what happens outside (as well as within) government. As new issues arise that require inter-departmental coordination, so new committees are created. The number of committees in which departments are represented is thus likely to tell us something about the contemporary priorities of collective decision-making structures. Such information could only be a starting point for analysis, of course, but it could nonetheless help to advance our knowledge and understanding of Britain's core executive.

Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD
Nicholas Allen https://orcid.org/0000-0002-3172-3506 Notes 1. The equal share was calculated by dividing the committee's weighted influence score by N + 1, where N was the total membership. The division by N + 1 was necessary because of the chair's double share. 2. As one respondent told us, the distinction between ministers who are full members and ministers who merely attend cabinet was one that, in practice, 'doesn't mean very much' (interviewee 1). 3. We also calculated post-2015 scores excluding the memberships of implementation task forces. The scores and rankings were not fundamentally different. 4. Although the new post-election committee system was first detailed in a list published in June 2015, the information was updated less than a month later with the addition of the Economic Affairs Committee's Airports Sub-Committee. Because of their proximity, we analysed the later July list.
5. Some of this information could in theory be established by consulting official minutes in the National Archives. But individual ministers' positions are generally not recorded, and the minutes relevant to our study will not be released for many years. 6. Those we interviewed included three former ministers and a very senior official. The three former ministers were all members of the coalition-era 'sextet' (Grice, 2012) and included at least one representative from each of the parties. The interviews were conducted on a non-attributable basis. The sacrifice in transparency was offset by the opportunity to speak to a number of figures with intimate knowledge of the Cameron-era cabinet-committee system.