<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Archiving and Interchange DTD v1.0 20120330//EN" "JATS-archivearticle1.dtd">
<article xmlns:xlink="http://www.w3.org/1999/xlink">
  <front>
    <journal-meta />
    <article-meta>
      <title-group>
        <article-title>Modeling of Necessity Entrepreneurship via General Equilibrium Approach*1</article-title>
      </title-group>
      <contrib-group>
        <contrib contrib-type="author">
          <string-name>Maria Fomenko</string-name>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <contrib contrib-type="author">
          <string-name>Alexander Shapoval</string-name>
          <email>abshapoval@gmail.com</email>
          <xref ref-type="aff" rid="aff0">0</xref>
        </contrib>
        <aff id="aff0">
          <label>0</label>
          <institution>National Research University Higher School of Economics</institution>
          ,
          <addr-line>Myasnitskaya str. 20, Moscow</addr-line>
          ,
          <country country="RU">Russia</country>
        </aff>
      </contrib-group>
      <abstract>
        <p>We construct a structural model of the occupational choice under unemployment, giving a natural definition of necessity entrepreneurs as individuals who fail to find a salaried job, but running business, they are able to earn more than the unemployment benefit. The existence of the necessity entrepreneurs shrinks unemployment in the economy and positively affects the welfare.</p>
      </abstract>
      <kwd-group>
        <kwd>Necessity Entrepreneurs</kwd>
        <kwd>Occupational Choice</kwd>
        <kwd>General Equilibrium Model</kwd>
      </kwd-group>
    </article-meta>
  </front>
  <body>
    <sec id="sec-1">
      <title>Introduction</title>
      <p>Economists frequently study entrepreneurship in the context of the economic
development [1,2]. The relationship between entrepreneurship and economic development
is multidimensional [3]. In particular, an innovative entrepreneurship positively
affects the economic development. An opposite effect is likely related to necessity
entrepreneurs, who prefer paid employment but fail to get a job offer associated with
their expectations. The role of necessity entrepreneurs in the economic development
is difficult to estimate primary because their definition requires refinement and
preciseness [4].</p>
      <p>This paper brings a twofold contribution into the analysis of necessity
entrepreneurship. On one hand, we propose a simple structural model that defines the
necessity entrepreneurs in a natural way. On the other hand, we posit that this definition
corresponds to our expectations regarding necessity entrepreneurship in the Russian
Federation.</p>
      <p>In 1978, Lukas proposed an approach to modelling of necessity entrepreneurship,
considered now as canonical [5]. According to this approach, individuals perform the
occupational choice between entrepreneurship and a salaried job, choosing the
alternative that gives them a larger income. In the equilibrium, more talented individuals
run a firm, whereas the other individuals end up with the paid employment. We
extend this construction to the economy with unemployed agents. Then a part of
indi*Copyright © 2019 for this paper by its authors. Use permitted under Creative
Commons License Attribution 4.0 International (CC BY 4.0).</p>
    </sec>
    <sec id="sec-2">
      <title>Basic Model</title>
      <sec id="sec-2-1">
        <title>Economy</title>
        <p>viduals applied for a job are rejected, but, turning to entrepreneurship, earn more than
the unemployment benefit. This part forms the set of necessity entrepreneurs.
We consider a single-sector closed economy. In this sector, single-product firms
produce varieties of a differentiated good competing monopolistically. There are L
individuals in the economy. Aiming at higher profit, they perform the occupational choice
between entrepreneurship and the entrance into the labour market. The labour market
choice is risky, since a salaried job is not guaranteed. The application for a job can
fail. In this case, the individual secures the unemployment benefit, but switches to
entrepreneurship, if the latter is more profitable. The unemployment benefit is fixed
by the central planner to a prescribed level by taxing wages and profits in an
appropriate way.</p>
        <p>Individuals are assumed to be heterogeneous with respect to their entrepreneurial
abilities.
2.2</p>
      </sec>
      <sec id="sec-2-2">
        <title>Supply and Demand</title>
        <p>We assume that the individuals are homogeneous as consumers. They are endowed by
a separable additive utility function with a constant elasticity of substitution between
varieties of the differentiated good. Any mechanisms of the money transition between
time stages (credits, deposits, et. cetera) are absent; therefore, the consumers spent
money completely at each stage.</p>
        <p>The supply is also modelled by simple tools. Firms require labour as a single
production factor. The production function depends linearly in labour supplied by
individuals in inelastic way. The variable costs are inverse to entrepreneurial abilities of
the firm manager. Involving into the monopolistic competition, the firm clears the
market of its variety by tuning the price.</p>
        <p>The free entry and exit conditions regulate the number of firms in the economy.</p>
        <p>We show that unemployment is observed in equilibrium. As soon as the wages are
agreed, firms lose profits when hiring new workers for arbitrary positive
compensation. The origin of this phenomenon is drawn on the assumption regarding a
negligible size of each market agent with respect to the market in whole. As usual, we model
that every agent is unable to affect market aggregates by individual actions. Then the
demand remains unchanged, if some firm hires a new worker. Under stable market
aggregates, which, in particular, include wages, this new worker has nothing to
produce. Small costs associated with this worker do not play a role at all.
2.3</p>
      </sec>
      <sec id="sec-2-3">
        <title>Occupational Choice and Timing</title>
        <p>We assume that the occupational choice is performed in two stages. The
maximization of the income underlies the choice at the both stages. The sequential decisions are
based on the backward induction. At the first stage, individuals correctly anticipate
the choice of all agents at the second stage. In particular, the individuals optimize
their second stage decision for all outcomes of the first stages parameterized by a
single quantity. As a result, the second stage decision depends on the first stage
decision. It is taken, aiming to maximize the sum of the incomes obtained at each stage,
where the future income is discounted by a factor that is less than one.</p>
        <p>Evidently, the individuals, who are talented enough to run a firm and earn profit
exceeding the wages, decide to become entrepreneurs from the very beginning. On
the contrary, the individuals, who as entrepreneurs end up with profits that are lesser
than the unemployment benefit, definitely prefer the labour market over
entrepreneurship. However, some individuals, choosing entrepreneurship, can earn the profit that
is greater than the unemployment benefit, but less than the wages. Their choice
requires more detailed consideration.</p>
        <p>We assume that the decisions of the individuals are ordered with respect to their
entrepreneurial abilities. Namely, if an individual with entrepreneurial abilities 
finds profitable to run a firm, then more talented individuals also prefer to run a firm.
Analogously, if an individual with entrepreneurial abilities  finds reasonable to
apply for a job, then less talented entrepreneurs behave in the same manner. Under these
assumptions, individuals whose potential income as entrepreneurs only slightly
exceeds the unemployment benefit would prefer the labour market over
entrepreneurship at the first stage. Their gain from the job offer exceeds the losses from the
possible unemployment. If the latter occur, she has time to alter her decision at switch to
entrepreneurship at the second stage.</p>
        <p>We also believe that at the second stage, the individuals avoid risk and choose
entrepreneurship if it allows obtain the income that is greater than the unemployment
benefit. With this assumption in mind, we find an individual who is indifferent to the
second stage choice. Her entrepreneurial abilities solve the algebraic equation that
equalizes the after-tax-wages and the expected income of the labour market candidate.
The equation determining an indifferent individual at the first stage involves the same
idea but requires a certain generalization: now the discounted sum of the profits
equalizes the expected discounted income of the labour market candidate. The
abilities of this indifferent entrepreneur indicate the threshold between entrepreneurs and
non-entrepreneurs. We note that the abilities of the indifferent entrepreneurs found at
the second stage determine only a weak threshold at the first stage. Nobody with
lesser abilities chooses entrepreneurship, but some individuals with larger abilities end up
as workers. They avoid entrepreneurship at the first stage because fail to secure the
profit that exceeds the wages. As labour market candidates, they get the job offer at
the first stage and keep it at the second stage. The underlying mathematical
computation admits that the threshold abilities decrease from the first to the second stage. In
other words, deciding to run a firm at the first stage, the individual repeat her choice
at the second stage.</p>
        <p>Simplifying the model, we assume that the individuals are homogeneous as
workers: they are equally productive. This immediately equalizes the equilibrium wages.
However, we assert that the alternative between a former worker and a former
unemployed agent is resolved in favour of the worker when a firm chooses its employees at
the second stage.
Equilibrium consists of the set of the demands, the prices, the number of firms, and
the threshold abilities arising at the both stages such that each market cannot improve
the gain by deviation from the corresponding choice. This is a standard Nash
equilibrium used in the monopolistic competition theory. We establish the correctness of the
formulated problem, proving the existence and uniqueness of the threshold abilities.
This implies the existence and uniqueness of the other equilibrium variables. We also
find that, as expected, in equilibrium, a part of entrepreneurs earn the income that lies
between the unemployment benefit and the income of the workers. In other words, the
model does explain the existence of the necessity entrepreneurship through the
occupational choice threaten by unemployment.</p>
        <p>The first stage generates an intermediate low boundary I of the income of
entrepreneurs. As we discussed above, this boundary is located between the unemployment
benefit b and the income of workers (1-)w, where  is the tax rate. The individual
earning income I is indifferent between two options: entrepreneurship and risky
search for job that can be switched to entrepreneurship later. The losses from the
unsuccessful job application precisely balance the gains from the job offer. The
mathematical formulation is delegated into the Appendix.</p>
        <p>
          We posit that necessity entrepreneurs affect positively on economy, decreasing the
unemployment rate. If the central planner had the opportunity to prescribe
occupational choice, (s)he should motivate managers of the firms to reject the applications
from those workers whose entrepreneurial abilities are relatively large. This measure
would increase the number of the entrepreneurs in the economy. However, the
assumption regarding the homogeneity of workers is considered to simplify the
modelling. In reality, the workers are heterogeneous. Moreover, one would expect that more
successful entrepreneurs typically demonstrate a better output as workers. Therefore,
our model overestimates the number of entrepreneurs in the economy.
We are thankful to D. Pokrovsky (HSE) and V. Goncharenko (HSE) for their valuable
comments and criticism.
(
          <xref ref-type="bibr" rid="ref1">1</xref>
          )
(
          <xref ref-type="bibr" rid="ref2">2</xref>
          )
where  φ is the price charged by a firm that is run by an entrepreneur with abilities
 , and σ ∈ (1; +∞) characterizes the elasticity of substitution between varieties of
the differential good, and   (φ) is the number of entrepreneurs with abilities φ.
        </p>
        <p>The maximization of the profit leads to the price</p>
      </sec>
    </sec>
    <sec id="sec-3">
      <title>Acknowledgement References</title>
    </sec>
    <sec id="sec-4">
      <title>Appendix. Mathematical formulation of the equilibrium</title>
      <p>Maximization of the demand  φ by an individual with income  results in the
equation:
  ∫0∞  1−   ( )</p>
      <p>=  −  ,
 φ = (σσ−1)φ
charged by the firm that incurs a relative cost  per a unit of output;  is
understood as wages of workers.</p>
      <p>The balance between workers   earned after tax wages (1-)w and unemployed
agents   endowed by the benefit b is given by the equation:

where α ∈ (0; 1)indicates the taxes applied to workers and entrepreneurs.</p>
      <p>Let Γ(φ) be the fraction of individuals whose entrepreneurial abilities are at most
φ;  0 and  1 be the threshold at stages 0 and 1 respectively. We put
  =  σ</p>
      <p>(σ−1) ,
∞</p>
      <p>(σ−1)
 1 = (1 − (σ−1) +ασ 1−Γ( 0)
1−Γ( 1))∫ 0 φσ−1 Γ(φ)+ ∫ 0
 1
∞ φσ−1 Γ(φ)
Then the profits πφ,1 of the firm run by an individual with the abilities φ at stage 1
The cutoff equation at stage 1 is</p>
      <p>Γ( 0)Γ( 1)
 1 ασ Γ( 0)+(σ−1) Γ( 1)
where  0 is considered as a parameter.</p>
      <p>Let A &lt; 1 be the factor that discount the second stage profit. Then the cutoff
equation at stage 0 is
(1 −  )( 0
 −1  0Γ0</p>
      <p>
        We pose conditions on the model parameters such that given w/b, , Γ(φ), and ,
the system of equations (7), (8) has a unique solution (t0, t1). This solution determines
the equilibrium distribution   ( ) of entrepreneurs over their abilities, the optimal
demands via (
        <xref ref-type="bibr" rid="ref1">1</xref>
        ), and the profits πφ,1 gained at stage 1.
(
        <xref ref-type="bibr" rid="ref3">3</xref>
        )
(
        <xref ref-type="bibr" rid="ref4">4</xref>
        )
(
        <xref ref-type="bibr" rid="ref5">5</xref>
        )
(6)
(7)
      </p>
    </sec>
  </body>
  <back>
    <ref-list>
      <ref id="ref1">
        <mixed-citation>
          1.
          <string-name>
            <surname>Glaeser</surname>
          </string-name>
          , E.:
          <article-title>Entrepreneurship and the City</article-title>
          . NBER Working Paper No.
          <volume>13551</volume>
          (
          <year>2007</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref2">
        <mixed-citation>
          2.
          <string-name>
            <surname>Chatterji</surname>
            ,
            <given-names>A.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Glaeser</surname>
            ,
            <given-names>E</given-names>
          </string-name>
          , Kerr,
          <string-name>
            <surname>W.</surname>
          </string-name>
          :
          <article-title>Clusters of entrepreneurship and innovation</article-title>
          .
          <source>Innovation Policy and the Economy</source>
          , vol.
          <volume>14</volume>
          , pp.
          <fpage>129</fpage>
          -
          <lpage>166</lpage>
          (
          <year>2014</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref3">
        <mixed-citation>
          3.
          <string-name>
            <surname>Reynolds</surname>
            ,
            <given-names>P. D.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Autio</surname>
            ,
            <given-names>E.</given-names>
          </string-name>
          ,
          <string-name>
            <surname>Cox</surname>
            ,
            <given-names>L. W.</given-names>
          </string-name>
          :
          <source>Global Entrepreneurship Monitor 2002 Executive Report. Global Entrepreneurship Research Association</source>
          (
          <year>2003</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref4">
        <mixed-citation>
          4.
          <string-name>
            <surname>Poschke</surname>
            ,
            <given-names>M.</given-names>
          </string-name>
          :
          <article-title>Entrepreneurs out of necessity: a snapshot</article-title>
          .
          <source>Applied Economics Letters</source>
          , vol.
          <volume>20</volume>
          , pp.
          <fpage>658</fpage>
          -
          <lpage>663</lpage>
          (
          <year>2013</year>
          ).
        </mixed-citation>
      </ref>
      <ref id="ref5">
        <mixed-citation>
          5.
          <string-name>
            <surname>Lukas</surname>
            ,
            <given-names>E. R. G.</given-names>
          </string-name>
          :
          <article-title>On the size distribution of business firms</article-title>
          .
          <source>The Bell Journal of Economics</source>
          , vol.
          <volume>9</volume>
          , pp.
          <fpage>508</fpage>
          -
          <lpage>523</lpage>
          (
          <year>1978</year>
          ).
        </mixed-citation>
      </ref>
    </ref-list>
  </back>
</article>