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  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>The Use of Agent-based Simulation of Public Policy Design to Study the Value Alignment Problem</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Pablo Noriega</string-name>
          <email>pablo@iiia.csic.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Enric Plaza</string-name>
          <email>enric@iiia.csic.es</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>IIIA-CSIC</institution>
          ,
          <addr-line>Barcelona, Catalonia</addr-line>
          ,
          <country country="ES">Spain</country>
        </aff>
      </contrib-group>
      <pub-date>
        <year>2022</year>
      </pub-date>
      <fpage>130</fpage>
      <lpage>139</lpage>
      <abstract>
        <p>We propose to use agent-based simulation (ABS) of public policies to explore fundamental and practical issues associated with the role of values in the governance of autonomous artificial systems. Value Alignment Problem (VAP), AI governance, value engineering, agent-based simulation, public policy Intelligent Systems. More technically, to address the “Value Alignment Problem” (VAP), that S. Russell characterised as “designing and building autonomous artificially intelligent systems (AIS) whose behaviour is, “provably aligned with human values” [1].1 This paper is an argument in favour of an experimental approach to VAP, using agent-based simulation (ABS) of public policy design (Sec. 2) to identify the the key components of VAP (Sec. 3) and explore the way value engineering can be addressed in practice (see Sec. 4). We have discussed some of these ideas before in [3, 4] and Perelló's PhD. dissertation [5] develops some of the underlying intuitions. We illustrate our proposal with the case of residential use of water in a medium size city involving households that demand and use water, a utility company that provides the service and the city government that oversees that the service is provided according to policy.2 Proceedings of Artificial Intelligence Governance Ethics and Law (AIGEL), Reviewed, Selected Papers. November 02 htp:/ceur-ws.org CEUR Workshop Proceedings (CEUR-WS.org) ISN1613-073 1We find that Russell's phrasing of VAP's in terms of alignment with human values (in [1]) is better suited for technical discussion than the more generic beneficial (in [2]). Moreover, we understand “provably aligned” not in proof-theoretic terms but rather as an objective way of measuring to what extent the behaviour of an AIS is consistent with a specif set of values. 2See [6, 5] for a detailed discussion</p>
      </abstract>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>1. Introduction</title>
      <p>The raison d’être of Artificial Intelligence is the design and construction of autonomous artefacts.
Such autonomy is the source of AI’s main contributions and concerns, hence the relevance
of devising ways to harness it. One way to achieve this is to engineer values into Artificial
CEUR
Workshop
Proceedings</p>
    </sec>
    <sec id="sec-2">
      <title>2. Modelling policy design as a value-alignment problem</title>
      <p>
        Given a policy domain (urban use of water) and a group of stakeholders (households, utility
company and city hall), a policy is an intervention that intends to improve the state of afairs.
Thus, policy design involves the identification and the articulation of means and ends (that
conform a policy intervention), followed by an assessment that such intervention is actually
conducive to the intended improvement [
        <xref ref-type="bibr" rid="ref7">7</xref>
        ].
      </p>
      <p>Values determine, in the policy itself, what is an improvement, whether an intervention
succeeds in achieving the improvement through appropriate instruments, and whether
stakeholders are satisfied with the intervention. Consequently, policy design has to model, on the
one hand, how values are involved in the decision-making of those individual agents whose
collective activity is being afected by a policy; and, on the other, how values are involved in
the governance of that collective behaviour —that is, in the design of the policy itself.</p>
      <p>
        Policy design is a complex problem —mainly because several variables with complex
interactions determine the activity and its efects and several (often conflicting) motivations and
interests are in play— involving factual and ethical decisions (cf. H. Simon [
        <xref ref-type="bibr" rid="ref8">8</xref>
        ]). Simulation,
being able to deal with such complexity and trade-ofs experimentally, is arguably a reasonable
methodological approach to policy design [
        <xref ref-type="bibr" rid="ref4 ref9">9, 4</xref>
        ]. Agent-based simulation (ABS) is an appropriate
type of simulation for policy design because it separates design concerns in the modelling of
individuals and in the modelling of collective action.
      </p>
      <p>In this context, ABS for policy interventions can be seen as a particular form of the VAP: It is
a design process problem with the two main tasks embedding values in an AIS and assessing
that the behaviour of the system is objectively aligned with those values. In fact, however,
value-driven policy modelling has the added advantage of a dual perspective of value embedding:
how to embed values in the decision model of an agent; and how to embed values in the means
and ends of a policy intervention. Alignment, in turn, can be studied in the outcomes of the
simulation by looking at the degree of satisfaction of individual agents with the outcomes of
the policy with respect to the agent’s individual values, and in the efectiveness of the policy
intervention in the fulfilment of the postulated values. In fact, ABS provides an experimental
framework for testing the adequacy of these models.</p>
    </sec>
    <sec id="sec-3">
      <title>3. Making the VAP operational in policy modelling</title>
      <p>From the perspective of policy design, the point of ABS is to identify a course of action that is
efective in reaching some desirable goals, through means that have reasonable trade-ofs and
are acceptable to stakeholders. Values play a key role in this process because they provide the
central elements of the simulation. In fact, having some explicit values in mind, suggest which
elements must be observable through the simulation (in order to assess and compare outcomes
of simulation runs). Values also serve to identify what actions are conducive to desirable or
undesirable outcomes, and therefore values determine not only that such actions be included in
the simulation but also to include the governance means that harness policy subject actions
toward the desirable outcomes. Along these lines, values should be involved in the modelling of
policy subjects: an agent chooses to perform an action when that the action satisfies the needs
and preferences (i.e. values) of that individual. Finally, as suggested in the previous section,
values determine diferent perspectives for the assessment of the outcomes of simulation runs;
thus, one needs to model whether an intervention leads to desirable states-of-the-world, the
relative advantages of (equally efective) interventions, and whether a given intervention is
more or less compatible with the values and preferences of the diferent stakeholders (including
direct policy-design stakeholders as well as individual policy subjects).</p>
      <p>
        In order to make this role of values operational for simulation purposes one needs to address
two design concerns: on the one hand, modelling of the policy domain and the behaviour of
agents; and on the other, engineering of values into those models ( Fig. 4). In technical terms
the policy domain is modelled as an online institution and policy subjects as the autonomous
agents that interact within it (see [
        <xref ref-type="bibr" rid="ref10">10</xref>
        ]). The engineering of values can be addressed as outlined
below and discussed in [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ].
      </p>
      <p>Modelling policy domain and policy. subjects Without going into details, the policy
domain needs to include a Physical Model —that captures what happens in that fragment of the
real world (the policy domain) that has to be taken into account for the design of a policy— and
a Governance Model —that captures the artificial constraints that govern the interactions of
policy subjects. For example, in the case of urban water policy, the Physical Model contains an
abstraction of the real-world conditions that correspond to the supply and use of water in a city
(the total supply of water, a number of households with their specific economic, demographic
and water use profiles, the cost of treating a ton of water, how many litres are used to take a
regular shower, how much water is saved with an ecological toilet and the cost of buying one;
and so on). The Governance Model includes the conventions (norms,regulations and even social
practices) that bear upon water use and supply (the way invoices are calculated and presented
to households, the standards for water quality, subsidies for refurbishing household appliances,
contracting conditions for water utilities,etc).</p>
      <p>
        The simulation of policy subjects usually amounts to some assumptions about the population
of agents and the modelling of their decision-making. The core modelling assumes –in our
proposal– that an agent takes a policy-enabled action only when opportunity, capability and
motivation concur. In our example, households are defined by a socio-demographic profile (data
like the number of household-members, age, sex, income; based on empirical data like census,
administrative actions, etc) and a value profile (that characterises the preferences and priorities
of households; based on more or less standard value taxonomies like Schwartz [
        <xref ref-type="bibr" rid="ref12">12</xref>
        ]) that will be
involved in modelling the motivation part of decision-making.3
      </p>
      <p>Policy intervention. A policy intervention is a selection of policy instruments whose efects
on the state of the world are to be assessed (e.g., introducing an incrementally progressive fare
for household water use together with subsidies for purchasing water-saving devices and a
campaign to foster the adoption of water-saving practices in order to reduce household water
consumption).</p>
      <p>Engineering values. The point of this process is to translate an abstract notion of value
into concrete constructs that may be embedded in a policy intervention, in the domain model
3The modelling of capability is linked to the socio-demographic profile of the agent and constrained by the governance
conventions. Opportunity has to do with the physical constraints, the state of the world and the current conditions
of the household profile variables.
and as part of the agent decision-model of individual policy subjects.</p>
      <p>A. The translation process. It can be organised as a cycle with three main stages: value
choice, value interpretation and value-alignment assessment, as follows:</p>
      <p>1. Value choice. Identifying those values that are appropriate for the policy domain and those
stakeholders whose values ought to be represented in the policy that is being designed. Urban
water use would prioritise values like sustainability, healthiness, security, fairness, eficiency,
etc; and the stakeholders are not only the policy subjects that we are explicitly modelling
(households and water utility companies) but also those that are involved in the policy design
(the city administration that will be responsible for the policy deployment and follow up, the
politicians who promote and negotiate the policy and other indirect stakeholders like industry
and agriculture, climate advocacy groups, banks).</p>
      <p>2. Value interpretation. This stage addresses two problems:
1. Making values observable. That is, turn a label that stands for an abstract value into
a feature that is measurable. Namely a goal or a set of goals that is motivated and
legitimised by the value. It is convenient to distinguish goals that are consensual (because
they correspond to values that should be embedded in the policy, independently of the
individual values of stakeholders) and those goals that are desirable for each stakeholder.
For instance, in our example, the goal to reduce individual water consumption to a
certain per-capital-annual volume may be one goal that stands for the consensual value
of sustainability.
2. Instrumenting values. That is, identify means to achieve the intended goals. Since the
actions of agents is what leads or detracts from the satisfaction of goals, the
instrumentation of a value is the modulation of those actions that afect those goals. Thus to achieve
sustainability, one may want to promote the adoption of water saving devices as a way
of reducing individual water use; and for this purpose a city may decide to regulate
sanitation standards for new housing or provide subsidies for retrofitting and start a
campaign to motivate such adoption. In fact, we assume that instruments can only be
of three types: aford or prevent actions (specified in the physical model); promote or
discourage actions (in the governance model), and provide information that may facilitate
the decision-making of participants towards those actions (from the governance model
and through the physical model).</p>
      <p>Figure 1 shows the goal decomposition process that starts with the consensual policy-maker’s
domain-specific values (on the left) until reaching (on the right) the salient policy goals. For
each policy goal, the diagram also shows some of the corresponding observable indicators and
some instruments that impact on those indicators.</p>
      <p>3. Value-alignment assessment. Establish the conventions to determine to what degree a
specific value is being fulfilled and then define a way of combining the satisfaction of a set of
values to determine the degree to which all the values are being fulfilled. This can be achieved in
diferent ways but one may think of this alignment assessment as a multi-objective optimisation
process of sorts. First, for each value one can postulate a threshold of satisfaction (that we call
an “aspiration level”) —e.g. a 15% reduction of domestic water use over the next five years—
and a way of qualifying to what extent any potential state of afairs may be better or worse
—a utility-like function, for example, that ranks diferent water reduction rates— thus defining
some kind satisfaction function for each value. Second, one needs an aggregation function that
determines the degree of satisfaction of all the values —for instance the satisfycing aggregation
function in Fig. 2.</p>
      <p>
        We propose three kinds of assessment of a policy intervention: efectiveness (to what extent
the values are being served), adequacy (trade-ofs in the choice of instruments), and acceptability
(alignment with stakeholders’ values) —see [
        <xref ref-type="bibr" rid="ref13">13</xref>
        ] for a similar distinction of relevant assessment
criteria, specific to the water domain.
      </p>
      <p>B. Embedding values in the models. Once the values are translated into concrete constructs
through the process just described, these are made operational in two contexts: First, in the
modelling individual value-aligned behaviour in each simulated policy subject. This can be
accomplished in three ways: as a deterministic reaction to certain situations, as a learning
mechanism that leads to consistent behaviour that is value aligned, or as a cognitive component
in the agent reasoning that makes values bear upon the selection of actions, as illustrated in Fig.
3.</p>
      <p>Second, values become operational in the policy itself: as part of the policy domain model
—as afordances and constraints of the physical and governance models— as part of a policy
intervention (through the features that serve to measure values and the selection of policy
instruments), and as the way of assessing the alignment of an intervention (as sketched in Fig.
4).</p>
    </sec>
    <sec id="sec-4">
      <title>4. Agent-based simulation of policy interventions</title>
      <p>The purpose of using ABS to design a policy is to provide experimental evidence to support
the choice of a policy intervention. The point is to test, in a systematic way, diferent policy
interventions —combination of policy instruments— and identify the ones that lead to the best
end results. Fig. 4 summarises the modelling assumptions and describes the simulation cycle.
Experimental settings. There are four main components:
1. Starting conditions and evolution. These include:</p>
      <p>(i) all the parameters of the physical model that hold at time 0 (including a starting
population of policy subjects);
(ii) all the governance conventions (norms, regulations, enforcement mechanisms) that
are active at time 0 and their corresponding parameters; and
(iii) a specification to account for the evolution of the state of the world (e.g.
environmental, economic and demographic changes).
2. Policy intervention (or, more intuitively, a sensible list of instruments). For each instrument
in the intervention:
(i) the list of indicators of the state of the world that are afected with the enactment of
the instrument;
(ii) the parameters associated with each instrument that are worth testing; and
(iii) a measure of the most significant positive and negative efects of the instrument on
indicators and policy goals.
3. Assessment assumptions. We distinguish assessment with respect to the consensual values
and with respect to the values of the individual stakeholders.</p>
      <p>(i) Consensual value interpretation: The definition of (consensual) policy goals and
their assessment features: aspiration levels, degree of satisfaction and aggregation
functions. These assumptions are used in the efectiveness and adequacy assessments
(ii) Value interpretations of stakeholders: The goals, satisfaction and aggregation
functions that are specific for each of those stakeholders who participate directly in
the design of the policy (city hall, utility companies, special interest groups, and
so on). These assessment features are involved in the adequacy and acceptability
assessments.
(iii) Policy subjects’ value interpretation: The values and assessment features that belong
to each simulated policy subject type. These will be used in their individual decision
models and in the acceptability assessment.
4. Assessment functions. We will to use three measures to assess diferent aspects of achieving
a goal.</p>
      <p>(i) Efectiveness, to measure how successful is the policy intervention in achieving the
consensual goals;
(ii) Adequacy, that determines whether the means to achieve those goals are adequate
in terms of their collateral efects (in order to assess the trade-ofs between
interventions);and
(iii) Acceptance, that measures the degree to which the policy intervention aligns with
the values of simulated policy subjects as well as with those of the direct stakeholders
that participate in the policy design and negotiation process.</p>
      <p>
        Testing cycle. Given a set of starting conditions a policy intervention is evaluated with
respect to a set of assumptions about value interpretation, and assessment. Simulation allows
to explore the efects of changing parameters of the policy intervention instruments, changing
the instruments, changing value choices, interpretation, instrumentation and assessment, and
also modifying the starting conditions. These experiments are meant to provide support for
the comparison of policy interventions, and in this way contribute evidence towards policy
negotiation and deployment.
5. Closing remarks
1. Values as an explicit design feature. As we argued in the introduction values are
an essential feature of policy design. As far as the modelling process is concerned, values
elucidate what entities (objects) need to become part of the physical model of the domain,
what entities need to be observable in the simulated state of the world, what actions need
to be aforded and what constraints need to be implemented. Values may also be used
to elucidate the analogous features in the design of a large variety of artificial intelligent
systems. For instance, the ideas we outlined in this paper are directly applicable to artificial
intelligent systems that involve the online coordination of autonomous agents, as discussed in [
        <xref ref-type="bibr" rid="ref11">11</xref>
        ].
2. An experimental approach to value engineering. In the previous section, we gave
a shallow description of the process of engineering values into a simulated multiagent
system. This outline would need to be fleshed out for designing a particular policy through
sound simulation. However, these ideas may also be expanded to support an experimental
approach to value engineering by exploring alternative ways to address each of the tasks in
the valueengineering process. For instance alternative value aggregation functions; agent
architectures for ethical reasoning and so on. Such exercises should provide evidence for design
guidelines and heuristics for value engineering.
3. Value-based governance of artificial systems. This paper can be read as an exercise of
modelling a value-based policy design process. However, the way we chose to model the policy
domain and the autonomous policy users can be extended to modelling of online systems
that involve autonomous agents that may be artificial or not. This way, the afordances and
constraints as well as the instruments that guide a policy intervention can be understood as
value-driven governance means that harness the autonomous behaviour of those entities within
the online system. Likewise, the way values are embedded in the decision-making of policy
subjects in this paper is but an simplified example of the process of engineering value-driven
behaviour into an autonomous artificial agent.
4. An AI-inspired theory of values. This paper is also an argument in favour of the
exploration of an AI-inspired theory of values. In particular, we envisage a re-examination of
conventional views on values in such a way that values may also be ascribed to artefacts having
self-driven behaviour within a social context. We claim one needs to take into account four
core concepts to articulate such theory: values, autonomy, governance, and collective action.
The interplay among these four concepts shapes the research landscape in which AI systems
can be value abiding. From a methodological standpoint, we believe that the approach to the
development of an AI-inspired theory of values may profit from available AI developments and
mirror the path followed in classical AI: a few well-chosen core concepts, multidisciplinary
work, building science along with engineering, and designing paradigmatic problems —and, as
we argue in this paper, value-driven policy design may be one of these.
      </p>
    </sec>
    <sec id="sec-5">
      <title>Acknowledgments</title>
      <p>Research for his paper is supported by EU
(HORIZON-EIC-2021-PATHFINDERCHALLENGES01) Project VALAWAI 101070930; the EU (NextGenerationEU/ PRTR program) and the Spanish
(MCIN/AEI /10.13039/501100011033 program) project VAE TED2021-131295B-C31; and CSIC’s
(Bilateral Collaboration Initiative i-LINK-TEC) project DESAFIA2030 BILTC22005.</p>
    </sec>
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