Wage differentials among Italian graduates.
Temporary versus permanent contracts
Irene Brunetti, Valeria Cirillo and Valentina Ferri
INAPP - National Institute for Public Policy Analysis
Il presente contributo è stato realizzato da INAPP in qualità di Organismo intermedio del PON SPAO con il contributo del FSE 2014-2020, Azione: 8.5.6
lOth International Academic Conference –
Global and Contemporary Trends in Social Science
6 November, 2018 - Barcellona
• European countries witnessed a significant expansion of temporary employment.
• In 2018, in EU, temporary contracts are 16% of total contracts; in Italy, 15,5%.
An increase of 400.000 temporary contracts with respect of 2017.
Motivations
4 6 8 10 12 14 16 18
% of Temporary Employment 2000-2017
(wage and salary workers)
ITA EU28
3
• Different working conditions for workers with the same level of competence should result in a wage premium for temporary workers to off set the disadvantages.
• The empirical evidence shows a wage penalty for temporary jobs.
• We investigate the temporary-permanent wage gap on graduates workers in the Italian labour market.
• We decompose the wage differential along the entire wage distribution.
Motivations
Wage differentials among Italian graduates. Temporary versus permanent contracts
Overview
• Related literature
• The metodology
• The empirical analysis
• Conclusions and future research.
Table of contents
5
THEORETICAL LITERATURE
• Temporary contracts can be stipulated to maximize workers' on the job effort.
Fixed-term contracts can have a positive effect on effort if workers perceive that the rehiring probability depends on past performance (Dolado, García- Serrano and Jimeno, 2002).
• Temporary employment is used by firms as a flexible mechanism to adjust employment to fluctuations in the business cycle (Blanchard and Landier, 2002).
• Temporary jobs can be used as a screening device. To hire workers with temporary contracts in order to screen them, and permanently retain the ones who proved to be more productive (OFlaherty and Siow, 1995; Portugal and Varejão, 2010; Faccini, 2014).
Related Literature
Wage differentials among Italian graduates. Temporary versus permanent contracts
EMPIRICAL LITERATURE
Theory of compensating wage differentials: a competitive labor market should reward any “adverse conditions” the workers face workers with the same level of competence should receive different wages if their working conditions are different: A positive wage differential for temporary workers (Rosen, 1974; Smith, 1979 for a review).
BUT
• A positive wage differential in favor of permanent workers (Jimeno and Toharia, 1993; Bentolila and Dolado, 1994; Booth and Francesconi, 2002;
Blanchard and Landier, 2002; Picchio,2008; Bosio, 2014; Dias da Silva and Turrini, 2015).
• The contract discrimination is higher at the bottom of the wage distribution and tend to decrease as considering higher quantiles (Mertens e McGinnity, 2005; Barbieri e Cutuli, 2009; Bosio, 2009; Comi and Grasseni, 2012).
Related Literature
7
THE ECONOMETRIC MODEL Mincer equation:
Three methods:
• One wage OLS equation including the type of contract as a dummy variable in the equation.
• Two wage OLS equations, one for temporary and another for permanent employees.
• First a probit selection equation, second a linear regression including the derived correcting factor, or the Heckman procedure at two stages (Heckman, 1979; Davia and Hernanz, 2004).
Wage differentials among Italian graduates. Temporary versus permanent contracts
The methodology
OAXACA-BLINDER Decomposition
• To disentangle the endowments and coefficients effects in the explanation of wage differentials and to evaluate the presence of discrimination in the rate of return for temporary contracts (Oaxaca, 1973; Blinder, 1973).
∗ ∗ ∗ )}
where the first term on the right-hand side of equation is the "explained component”, the second term is the "unexplained component“ (i.e. the wage discrimination).
• This approach assumes linearity, can only be applied to the mean of distribution, and it is sensitive to the choice of the base group.
• To overcome the first and second limits Alternative approach: RIF decomposition (Firpo et al., 2007).
The methodology
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Recentered Influence Function (RIF) Decomposition Two steps:
• The estimation of a RIF regression model of quantiles, where the RIF of a general distribution statistics v(f(x)) is given by the sum of the statistics itself and its Influence Function (IF).
• Apply a decomposition analogous to the Oaxaca – Blinder approach.
; ;
where is the total wage effect. Adding and subtracting the term ; in the last line of the previous equation, we get the following decomposition:
; ; ; .
• We are interested in the second term: a positive value indicates that the returns to temporary characteristics are lower than those of permanent and this obviously points out at “discrimination”. A negative value implies the reverse.
Wage differentials among Italian graduates. Temporary versus permanent contracts
The methodology
THE DATA
• Source: “ Inserimento Professionale dei Laureati “ (Istat).
• Year: 2015.
• Sample: 28000 graduates employees (17296 with permanent contract and 11048 with a temporary contract).
• Variable of interest: monthly net wage.
• Exclusion variable : final grade at college.
• Control variables (individual characteristcs and occupation charcteristics): gender, type of degree, fields of degree, part time/full time, sector of activity, occupation (ISCO08).
The empirical anlysis
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DESCRIPTIVE ANALYSIS
Wage differentials among Italian graduates. Temporary versus permanent contracts
DESCRIPTIVE ANALYSIS
Perm-Temp q10
Perm-Temp q50
Perm-Temp q90
Ln monthly net wage (full-time equivalent) 0.288 0.145 0.107
Ln monthly net wage (only full-time) 0.251 0.145 0.165
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Full time eq. Only full time workers
Contract Dummy (=1 if temp) -0.136***
(0.001)
-0.153***
(0.00)
Part time 0.069***
(0.002)
-0.510***
(0.00)
Grade of University degree 0.0013***
(0.00)
0.001***
(0.00)
Duration of studies 0.002***
(0.001)
0.002***
(0.004)
Master University degree .054***
(0.002)
0.060***
(0.00)
Female -0.063***
(0.00)
-0.064***
(0.00)
Work in the south -0.085***
(0.00)
-0.104***
(0.00)
Selection bias (Inverse Mill’s Ratio) -0.008*
(0.089)
-1.201***
(0.00)
Sectors Dummy YES YES
Occuparion Dummy YES YES
Fields of study Dummy YES YES
Intercept 1.038***
(0.001)
1.446***
(0.00)
N 26032 26032
OAXACA – BLINDER DECOMPOSITION
OB_FulltimeEquiv
Permanent 7.386***
(0.003)
Temporary 7.197***
(0.006)
Difference 0.188***
(0.007)
Explained 0.051***
(0.004)
Unexplained 0.137***
(0.006)
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RIF DECOMPOSITION
Note: Bbootstrapped standard errors; in parenthesis. ***, ** and * denote statistical significance at the .01, .05 and .10 levels, respectively
Wage differentials among Italian graduates. Temporary versus permanent contracts
10° percentile 50° percentile 90° percentile
Permanent 7.108*** 7.424*** 7.759***
(0.003) (0.002) (0.004)
Temporary 6.847*** 7.274*** 7.664***
(0.009) (0.003) (0.006)
Difference 0.261*** 0.150*** 0.095***
(0.010) (0.004) (0.008)
Explained 0.047*** 0.028*** 0.017***
(0.004) (0.002) (0.004)
Unexplained 0.214*** 0.122*** 0.078***
(0.009) (0.004) (0.007)
Conclusions
• Four years after graduation, to find a work means to find a temporary work and the final grade helps to find this job.
• Aftr controlling for possible selection bias, among graduates workers there is evidence of a penalty in terms of wage for temporary workers.
• The Oaxaca-Blinder decomposition shows that about 72% of the difference between temporary and permanent workers is due to the discrimination effect.
• The wage gap is higher at the bottom of the wage distribution.
Future Research
• To estimate two separeted two stage OLS wage equation : one for permanent and one for temporary workers.
Conclusions
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THANK YOU FOR YOUR ATTENTION
Wage differentials among Italian graduates. Temporary versus permanent contracts
Irene Brunetti –i.brunetti@inapp.org ; Valeria Cirillo –v.cirillo@inapp.org; Valentina Ferri– v.ferri@inapp.org