Unaddressed problems and research perspectives in scheduling blood collection from donors

Many optimisation problems arise in managing the Blood Donation (BD) supply chain. Most of them have been addressed in the literature, while other problems, e.g. donation scheduling, have not been sufficiently addressed so far. However, blood collection from donors may have a disruptive impact on the entire BD supply chain if not properly managed. For example, scheduling donation appointments based on some system metrics may improve the flow of blood units through the BD supply chain and increase the quality of service perceived by donors. In this short communication, we present the donation scheduling problem and highlight the lack of work in the literature that deals with this problem. Then, we analyse the impact of an unbalanced flow of blood units on the BD system and the benefits that may derive from a suitable appointment scheduling. Finally, we propose suggestions for future research in BD collection scheduling that may improve the BD process.     

Immigration and prices: quasi-experimental evidence from Syrian refugees in Turkey

We exploit the regional variation in the unexpected (or forced) inflow of Syrian refugees as a natural experiment to estimate the impact of immigration on consumer prices in Turkey. Using a difference-in-differences strategy and a comprehensive data set on the regional prices of CPI items, we find that general level of consumer prices has declined by approximately 2.5 % due to immigration. Prices of goods and services have declined in similar magnitudes. We highlight that the channel through which the price declines take place is the informal labor market. Syrian refugees supply inexpensive informal labor and, thus, substitute the informal native workers especially in informal-labor intensive sectors. We document that prices in these sectors have fallen by around 4 %, while the prices in the formal labor-intensive sectors have almost remained unchanged. Increase in the supply of informal immigrant workers generates labor cost advantages and keeps prices lower in the informal labor-intensive sectors.     

The welfaristic characterization of two-person revelation equilibria under imputational government

Given two players whose declarations about their private preferences are to be used in enforcing imputations, i.e. individually rational Pareto optima according to the declared preference profile, the Nash equilibria of the revelation game so defined always induce individually rational outcomes according to the true preferences, and for all such outcomes there is (and we construct) a Nash equilibrium declaration of preferences which induces precisely that outcome.We conjectured and proved the main result reported here in January, 1989, while M.R. Sertel was visiting at the Decision Sciences and Economics Departments, University of Pennsylvania, and was visited by S. Koray, who was kindly invited by the Wharton School. The hospitality of our hosts is gratefully acknowledged. Participants in the Game Theory course, DS901, in Spring 1989 at the Decision Sciences Department of the Wharton School are thanked hereby for being our first audience, and our special thanks go to Paul Kleindorfer, with whom M.R. Sertel shared the pleasure of giving this course, for his steady encouragement and his persuading us of the importance of our theorem from an experimental viewpoint. TÜBTAK and the Boaziçi University Research Fund. (The Scientific and Technical Research Council of Turkey) partially supported the preparation of this paper, and Bosfor Turizm kindly supported its presentation at the Annual Meeting of ASSET, Florence, Italy, October 1989. We hereby thank a thoughtful anonymous referee for comments which we believe to have led to improvements over an earlier (November 1989) version of this paper.     

Self-selective social choice functions

It is not uncommon that a society facing a choice problem has also to choose the choice rule itself. In such situations, when information about voters’ preferences is complete, the voters’ preferences on alternatives induce voters’ preferences over the set of available voting rules. Such a setting immediately gives rise to a natural question concerning consistency between these two levels of choice. If a choice rule employed to resolve the society’s original choice problem does not choose itself, when it is also used for choosing the choice rule, then this phenomenon can be regarded as inconsistency of this choice rule as it rejects itself according to its own rationale. Koray (Econometrica 68: 981–995, 2000) proved that the only neutral, unanimous universally self-selective social choice functions are the dictatorial ones. Here we introduce to our society a constitution, which rules out inefficient social choice rules. When inefficient social choice rules become unavailable for comparison, the property of self-selectivity becomes more interesting and we show that some non-trivial self-selective social choice functions do exist. Under certain assumptions on the constitution we describe all of them.     

Characterization of self-selective social choice functions on the tops-only domain

Self-selectivity is a new kind of consistency pertaining to social choice rules. It deals with the problem of whether a social choice rule selects itself from among other rival such rules when a society is also to choose the choice rule that it will employ in making its choice from a given set of alternatives. Koray [3] shows that a neutral and unanimous social choice function is universally self-selective if and only if it is dictatorial. In this paper, we confine the available social choice functions to the tops-only domain and examine whether such restriction allow us to escape the dictatoriality result. A neutral, unanimous, and tops-only social choice function, however, turns out to be self-selective relative to the tops-only domain if and only if it is top-monotonic, and thus again dictatorial. Received: 8 October 2001/Accepted: 4 June 2002     

Day-of-the-Week Effects in Subjective Well-Being: Does Selectivity Matter?

Individuals tend to self-report higher well-being levels on certain days of the week than they do on the remaining days, controlling for observables. Using the 2008 release of the British Household Panel Survey, we test whether this empirical observation suffers from selection bias. In other words, we examine if subjective well-being is correlated with unobserved characteristics that lead the individuals to take the interview on specific days of the week. We focus on two distinct well-being measures: job satisfaction and happiness. We provide convincing evidence for both of these measures that the interviews are not randomly distributed across the days of the week. In other words, individuals with certain unobserved characteristics tend to take the interviews selectively. We conclude that a considerable part of the day-of-the-week patterns can be explained by a standard “non-random sorting on unobservables” argument rather than “mood fluctuations”. This means that the day-of-the-week estimates reported in the literature are likely to be biased and should be treated cautiously.     

Technologie,délocalisations et tâches constitutives des professions au Royaume‐Uni

Les auteurs examinent l'évolution des tâches accomplies par les travailleurs au Royaume‐Uni entre 1997 et 2006, qu'elle soit due à une reconfiguration des professions elles‐mêmes (marge intensive) ou à une variation de leur part respective dans l'emploi (marge extensive). Ils se fondent notamment dans cet examen sur des données de la Skills Survey, enquête britannique sur les compétences. Leur analyse montre que la variation à la marge intensive est notable et aussi importante que la variation à la marge extensive. Une analyse économétrique fait ressortir en outre que le progrès technique joue un rôle dans l'évolution à la marge intensive, mais pas les délocalisations.     

Skill Acquisition in the Informal Economy and Schooling Decisions: Evidence from Emerging Economies

Informal jobs offer skill acquisition opportunities that may facilitate a future switch to formal employment for young workers. In this sense, informal training on the job may be a viable alternative to formal schooling in an economy with a large and diverse informal sector. In this paper, I investigate if these considerations are relevant for the schooling decisions of young individuals using panel data for 17 Latin American countries and micro‐level data for Turkey. Specifically, I ask if the prevalence of informal jobs distorts schooling attainment. I concentrate on three measures of schooling outcomes: (1) secondary education enrollment rate; (2) out‐of‐school rate for lower secondary school; and (3) tertiary education graduation rate. I find that the secondary education enrollment rate is negatively correlated with the size of the informal economy, whereas the out‐of‐school rate is positively correlated. Moreover, the tertiary education graduation rates tend to fall as the informal employment opportunities increase. This means that informal training on the job may be crowding out school education in developing countries. Policies that can potentially affect the size of the informal sector should take into consideration these second‐round effects on aggregate schooling outcomes.