What follows is a summary of P. Benoit, ‘Quirinius’, article in Dictionnaire de la Bible. Supplément vol. 9 (1979), 693-720.
 Luke 2:1-5: “In that days” is a vague indication and refers in principle to the “days of Herod” (1:5). “The whole inhabited world” means the Roman empire. Luke 2:2 in Greek reads as follows: αὕτη ἀπογραφὴ πρώτη ἐγένετο ἡγεμονεύοντος τῆς Συρίας Κυρηνίου. Without the article between “this” and “census” (according to the better tradition) the translation is: “This was the first census.” Some have suggested to take “first” as a comparative and to translate: “This census was before that of Quirinius being governor of Syria.” This is, strictly speaking, not impossible, but most critics reject it. The first three verses show three steps from general to particular.  However, the historical situation presupposed by these verses has severe historical problems.
I. The Censuses in the Roman Empire
One has to make a distinction between the census of Roman citizens and provincial citizens. The first disappeared in the 1st century BCE, the second marked the imperial period. The documents of Egypt show two operations: the declaration of properties for taxation and the declaration of persons for the poll tax.  Each head of the family declared who lived under his roof. This census for the poll tax happened every 14 years. However, this situation cannot be applied to Palestine without precaution. Moreover, the evidence does not point to a regular census in other provinces, let alone to one census in the whole empire ordered by Augustus.  But possibly Luke’s simple words refer to a more complex situation. It is known that Augustus liked to know the resources of the empire. Luke’s inexact statement can be viewed as an expression of the general politics of Augustus. He intended to make a parallel between the Saviour of the world and the universal dominium of Augustus.
II. A Roman Census in Judea in Herod’s Time?
Against a Roman census in Judea, not yet a Roman province at that time, serious objections could be raised, however not decisive.  The independance of Judea was relative. In the last troubled years of Herod a Roman census is easily explainable.  Alongside circumstantial evidence one can point to Tertullianus, who placed the census in the time of Sentius Saturninus. In any case, a Roman census in Judea in Herod’s time is possible.
III. Joseph and Mary go from Nazareth to Bethlehem
Another difficulty is why Joseph had to go to Bethlehem, the city of his ancestor David, 1000 years earlier. If everybody had done that, there would have been a mass migration. And why is Mary obliged to accompany Joseph? A possible answer is that the normal residence was not necessarily the same as the legal domicile, so that people had to return to their legal homes in the time of a census.  The theological aim of Luke (Bethlehem as the city of David) could conceal the fact that Bethlehem was Joseph’s legal domicile. It is not true that Joseph did not have a house in Bethlehem: Luke 2:7 could mean that there was no room in the communal room of Joseph’s family, so that they had to put the baby in a manger built in the wall. This also explains why Mary had to come to Bethlehem: her presence was not required for the census, but they expected to stay there after the census.
IV. The Career of P. Sulpicius Quirinius
The main problem of Luke’s account is the date of the governorship of Quirinius. According to Luke, Quirinius was governor before 4 BCE, but according to Josephus from 6 CE onwards. The career of Quirinius is too uncertain to settle the debate at once.  Two dates are certain: he was consul in 12 BCE and rector of Gaius Caesar from 1 to 4 CE. Of special interest is the war against the Homanadenses in southern Asia Minor, during which some believe Quirinius was governor of Syria from 11 to 7 BCE. This hypothesis, however, is complicated and fragile.  Nothing proves that he was governor of Syria during the war. This is also true of the hypothesis that he was proconsul of Asia at that time. A more favorable opinion is that Quirinius made war against the Homanadenses as governor of Galatia-Pamphylia. So there is no evidence that Quirinius was legate of Syria during that war; it is even less probable. Moreover, the date of the war is uncertain.
The only evidence of a governorship of Quirinius in Syria besides the Gospel of Luke is Josephus’ account and an inscription of an uncertain date.  Is it possible that Josephus was wrong in dating the census and the governorship in 6 CE? But maybe both Luke and Josephus were right and Quirinius was governor twice. The main argument for this hypothesis rests on the so called Titulus Tiburtinus.  However, this inscription is not necessarily about Quirinius, and it is not sure that it refers to a double governorship of Syria. Moreover, to be twice governor of the same province would be extraordinary. So a double governorship of Quirinius remains very doubtful. This reconciliation between Luke and Josephus should be abandoned.
V. The Testimony of Josephus
Josephus is well informed about the period of Herod the Great, but less about the period of Archelaus. [705-6] Doublets at the beginning and end of the reign of the latter might cast doubt on Josephus’ testimony.  Maybe Josephus does not deserve the unconditional trust that the same critics condemn in the case of Luke.
VI. Attempts to a Solution
A first solution is to place Quirinius in 4 BCE, because Josephus does not mention him in the Jewish War 2.117-118 (the text about the census in 6 CE).  However, this is extreme and difficult to accept, because in other places Josephus’ account is very clear. Another solution is to suppose a double intervention by Quirinius in 4 BCE and 6 CE and that Josephus is confused. The second time Quirinius was not the legate of Syria but a censitor or iuridicus. This solution has some attractiveness, but there are serious difficulties: a) A less likely interpretation of what Josephus says regarding the position of Quirinius.  b) The silence of Josephus about a census in 4 BCE and his mention of the acts of the procurator Sabinus (not Quirinius) in Palestine after Herod’s death. c) The difficulty to find a place for Quirinius as governor of Syria around 4 BCE. The names and years are:
- M. Titius: ca. 13 BCE until 11 or 9 BCE.
- C. Sentius Saturninus: 9-6 BCE. 
- P. Quinctilius Varus: 6-4/3 BCE.
- C. Gaius Caesar: 1 BCE – 4 CE.
- L. Volusius Saturninus: 4/5 CE.
- P. Sulpicius Quirinius: 6 CE-7 CE. 
- From 12 CE: Q. Caecilius Metellus Creticus Silvanus.
A desparate hypothesis is to place Quirinius as military legate alongside Saturninus or Varus, who would have been the legate of administrative affairs. This is an awkward construct and it is difficult to see why people such as Luke then should mention Quirinius in administrative matters. Variants of this hypothesis are also unlikely.  Only 4-1 BCE seems a possibility to place a first governorship of Quirinius. This solution has less against it, but there are difficulties: the double governorship and the double census is abnormal and it seems more and more likely that Quirinius was in 4-3 BCE governor of Galatia-Pamphylia. And in 4-1 BCE L. Calpurnius Piso was possibly governor of Syria. And, to conclude, Varus was governor until after Herod’s dead, so placing Quirinius in 4-1 BCE resolves nothing regarding Luke.  However, one could suppose that Quirinus had an extraordinary position in Syria under Saturninus and Varus before he became governor, so that Luke’s inaccuracy is pardonnable. For those who want to save Luke this is maybe the least unlikely solution.
It was not the aim of the evangelists to write a punctilious history. Luke himself gives an indication of that when he mentions the census in the time of Judas of Galilee as the census (Acts 5:37). Luke also places Theudas before Judas, although the first only revolted long after the years in which the story of Acts is supposed to have happened. So the simplest solution is that Luke spoke according to popular language, attaching the name of Quirinius correctly to the famous census, but transferring it about 10 years into the past.  This confusion is comprehensible when the birth of Jesus was already related to a census during the reign of Herod (cf. II). Possibly the census started in the time of Herod for the poll tax  and succeeded in the time of Quirinius as an estimation of fortunes.
In any case, Luke’s aim was to relate the birth of the Redeemer of the world to the organisation of the Roman world in the same time. So the scope of Luke is not untrue, although he does not offer exact information.
- Towards the end of the reign of Herod (between 7 and 4 BCE) a census of persons took place in Palestine, inspired by the politics of Augustus.
- Quirinius became governor only in 6 CE and led the census of fortunes. Luke anticipates a decade by naming Quirinius.
- The first census can be viewed as a preparation for the second and the incorporation of Judea in the Roman empire.  “Cela explique, ou si l’on veut excuse, l’anticipation de l’évangeliste qui, matériellement inexacte, n’en exprime pas moins ce qui lui tient à coeur: Jésus est né au moment où une mesure impériale, connue en Orient par le nom du fonctionnaire fameux qui la mena à bien, incorporait la Judée à l’empire et, selon le dessein de Dieu, préparait le terrain à la diffusion de l’Évangile.”
- I (CH) see a contradiction between conclusion 1 and point b on page 709.
- Bethlehem as the new residence of Joseph and Mary (cf. III) is unlikely in the light of Luke 2:39.
- Is Luke really that positive about the Roman census? Or does he make a contrast between the power of Augustus and the defenselessness of Jesus?