How does labor supply react to different tax rates? A field inquiry

Participants (96 students) were divided into three groups. Subjects in Group 1 were asked their labor supply, being their income burdened by a 25% tax rate. Then they were asked their labor supply if the tax rate were 40%. Subjects in G2 were asked their labor supply with a 25% tax rate, and subjects in G3 with a 40% tax rate. We first compared labor supplies within G1; then we compared labor supplies between G2 and G3. Finally we compared the two comparisons. In G1, subjects' labor supply is different, negatively related with the tax rate: this is probably due to how the questions are put, which suggest different answers. In fact, comparing G2 and G3, the labor supply is almost the same. Students who are part-time workers and students who are not supply different amounts of labor. There is no difference at all when comparing G2 and G3 as for non-working students, being the whole difference between G2 and G3 due to working students, who probably compare the tax rate they pay on their real income to the ones suggested in the questionnaire. Singling out non-biased responders, i.e. non-working students in G2 and G3, the tax rate on income, if given, independently of its level, does not influence the labor supply.labour supply, taxation, individual behaviour

Labour supply in presence of taxation financing public services. An experimental approach.

The paper illustrates the results of some experiments aiming to test the effect of taxation on the effort. Differently from previous experiments (Levy-Garboua et al., Sutter and Weck-Hannemann, Swenson), in our research the revenue of taxation is not depleted but employed, more realistically, to finance welfare provisions. The result is no more a reduction of effort, as in previous experiments, but a slight increase. This behavior is coherent with a theoretical model suggested by Bird in 2001.

Offerta di lavoro in presenza di tassazione: l'approccio sperimentale

La ricerca si propone di verificare l'universalità dei risultati (e quindi della teoria che li suffraga) di un piccolo ma altamente considerato corpus sperimentale, in base al quale l'erogazione dello sforzo lavorativo e' influenzata negativamente dall'imposizione fiscale. Tale verifica si rende necessaria in quanto gli esperimenti cui ci si riferisce appaiono viziati da presupposti fortemente limitativi che rendono non generalizzabili i risultati ottenuti: primo tra tutti l'inesistenza di una spesa per servizi pubblici in corrispondenza al prelievo fiscale. Viene esposta brevemente la teoria (ormai consolidata, anche se emarginata dal cosiddetto pensiero unico) sulla base della quale e' lecito attendersi risultati opposti a quelli ottenuti dagli esperimenti cui si e' accennato, in determinate ma plausibili circostanze. Si cerchera'  di qualificare questo risultato con ulteriori esperimenti.

Some differences in revealed behaviour under different inquiry methods

The experiment presented in this paper has two aims, both methodological. First, we want to check for the role of what we may call (after Carpenter et al., 2006) the they came to play effect. Second, we want to test whether the lab outcomes are confirmed by a questionnaire on a hypothetical similar scenario. In order to pursue our aims, we design an experiment made of four treatments: a lab-experiment with strategy method, a lab-experiment without strategy method, a questionnaire with strategy method and a questionnaire without strategy method. We may conclude that the lab results are definitively more reliable than the questionnaire ones only if you manage, in one way or the other, to get rid of the bias induced by the they came to play effect: a post-experiment questionnaire, containing explicit questions on the matter, may be a device.Experiments, questionnaire, come to play effect, strategy method