How Large Is the Private Sector in Africa? Evidence from National Accounts and Labor Markets

In recent years, the private sector has been recognized as a key engine of Africa's economic development. Yet, the most simple and fundamental question remains unanswered: how large is the African private sector? We present novel estimates of the size of the private sector in 50 African countries derived from the analysis of national accounts and labor market data. Our results point to a relatively large size of the African private sector. National account data shows that this accounts for about 2/3 of total investments, 4/5 of total consumption and 3/4 of total credit. In relative terms, large private sector countries are concentrated in Western Africa (Cote d'Ivoire, Guinea, Niger, Senegal and Togo), Central Africa (Cameroun, Republic of Congo) and Eastern Africa (Kenya, Sudan, Uganda and Tanzania), with the addition of Mauritius. Countries with small private sectors include a sample of oil-exporters (Algeria, Angola, Equatorial Guinea, Libya and Nigeria), some of the poorest countries in the continent (Burundi, Burkina Faso, Guinea Bissau, Mali and Sao Tome e Principe), Zambia and Botswana. Over the last ten years, the size of the private sector has been contracting significantly in oil exporting countries, although the variation in its size does not appear to be significantly correlated with growth performance. Labor market data reinforces the idea of a large private sector, which provides about 90% of total employment opportunities. However, most of this labor is informal and characterized by low productivity: permanent wage jobs in the private sector account on average for only 10% of total employment (a share similar to that provided by public administration and state owned enterprises). South Africa is the notable exception, with formal wage employment in the private sector representing 46% of total employment. Finally, we find evidence of negative private sector earning premiums, suggesting that market distortions abound. These are likely to prevent the efficient allocation of human resources, and to reduce the overall productivity of the African economies.private sector size, private sector development, private consumption, private investment, national accounts, private sector employment, private sector earnings, labor markets, Africa

Egg hatching at different temperatures and relative humidities in Idaea inquinata (Scopoli) (Lepidoptera: Geometridae)

Idaea inquinata (Scopoli) feeds mainly on dried plants, nevertheless, it is also a potential pest of stored products as it is able to develop on cereal products. The few references on the biology of this species do not deal with the influence of temperature and relative humidity on egg hatching. To fill this gap, groups of 100 eggs, 24-48 hours old, were exposed to five constant temperatures (17, 21, 26, 29 and 34±1°C), two relative humidities (35 and 70±5%) and a photoperiod of 0:24 (light:dark); ten tests were carried out. Each test was replicated four times and egg hatching was observed daily. The highest mean number of hatched eggs was observed at 26 and 29±1°C, 70±5% r.h. with 91.5 and 91.0 eggs, respectively. The lowest mean number of hatched eggs was 61.5 observed at 17°C and 70±5% r.h. The mean numbers of hatched eggs, 83.5, 77.5, 78.5 and 79.8 were similar at 21, 26, 29 and 34±1°C, 35±5% r.h., respectively. Eggs hatched between the sixth and the eighth day at all the temperatures tested, except for 17±1°C and 35±5% r.h., where hatching started on the twelfth day. At this temperature, the duration of the hatching period increased with increasing humidity: 11 d at 35% r.h. and 15 d at 70% r.h. Keywords: Egg, Hatching, Temperature, Relative humidity, Rusty wave mot

Effect of particle size of soft wheat flour on the development of Ephestia kuehniella Zeller (Lepidoptera : Pyralidae)

The effect of soft wheat flours, characterized by different particle size, protein and starch content, on the development of Ephestia kuehniella was studied. The attractiveness of the Substrata to first and third instar larvae was also considered. The different protein content of the flours did not significantly affect the development of E. kuehniella, nor did it affect the ability of the flours to attract larvae. In tests with soft wheat flours. with the same nutritional value but different particle size, the highest mean number of adults and the shortest developmental period were recorded on samples with greatest particle size (250-419 mu m). In order to test the attractiveness of soft wheat flour to larvae, a one-way olfactometer was used. There were no significant differences observed in the number of first and third instar larvae found on flours with different protein composition and particle size. Larvae of this species show limited mobility, in fact few individuals of either instar can reach the flour from a distance of 2 m. No larvae of either instar contacted the different substrata from a distance of 2.5 m

Development of rusty wave Idaea inquinata at constant temperatures, relative humidities and photoperiod

The development of larvae and pupae of Idaea inquinata was studied at two different temperatures, relative humidities and photoperiods. Tests were carried out at 26\ub11\ub0C and 29\ub11\ub0C, 50\ub15% RH and 70\ub15% RH, photoperiod 16:8 and 0:24 (light:dark). The highest mortality was observed at 29\ub0C, with 50 and 70% RH and a photoperiod of 16:8. The larval development was longest (64 days) at 26 and 29\ub11 \ub0C, 50\ub15% RH and the photoperiod 16:8, and shortest (23 days) at 29\ub11 \ub0C, 50 and 70\ub15% RH, and the 0:24 photoperiod. The analysis of the mean lengths of the development of larvae at different temperatures and relative humidity with the 16:8 photoperiod showed that the developmental time of larvae decreases with increasing relative humidity. This factor was significant, while the effect of the increase of temperature and the interaction between the temperature and relative humidity was not significant. At a 0:24 photoperiod a decrease of the developmental time of larvae was observed when temperature was increased, both at 50 and at 70% RH. The developmental time of pupae was between 4 and 15 days, the shortest mean developmental time with a highest number of alive individuals was observed at 29\ub11 \ub0C, and the photoperiod of 0:24, and both levels of relative humidity. The pupal developmental time showed small differences at the two relative humidities, with the exception of 26\ub11 \ub0C and photoperiod 16:8: at 50\ub15 % RH where the mean development time was 10.7 days (\ub11.3 SD), and at 70\ub15 % RH with mean duration of 9.1 days (\ub11.6 SD). The photoperiod influenced the length of development in I. inquinata as the shortest mean development periods were observed in the tests carried out with photoperiod (0:24)

Development of Cadra cautella (Walker), Corcyra cephalonica (Stainton), and Plodia interpunctella (H\ufcbner) (Lepidoptera Pyralidae) on Triticum monococcum L., T. dicoccum Schrank ex Schubler, and T. spelta L.

Groups of 100 eggs (laid 6-24 hours previously) of Cadra cautella, Corcyra cephalonica, and Plodia interpunctella were reared on 30 g of spikelets or kernels of Triticum monococcum, T. dicoccum, and T. spelta in a conditioned room at 26 \ub1 1 \ub0C, 70 \ub1 5 % r.h., and photoperiod 16:8 (L:D). A higher mean number of adults is observed when moths are reared on kernels, except for C. cephalonica on T. monococcum. The mean developmental time is longer with spikelets except when P. interpunctella is reared on T. monococcum. A low number of adults of the three species is observed on spikelets of T. dicoccum and T. spelta. In fact kernels are covered by glumes and inner glumes that hinder larvae feeding. The highest number of adults of C. cautella is observed on kernels of T. dicoccum (76.5 \ub1 7.8). Few adults of this species emerge from spikelets of T. dicoccum (4.7 \ub1 0.5) and T. spelta (4.5 \ub1 1.3). The mean developmental time is not significantly different among kernels (from 49.5 to 54.2 days) and among spikelets (from 61.5 to 66 days) of the different species of cereals. The highest number of C. cephalonica adults is observed on kernels and spikelets of T. monococcum and on kernels of T. dicoccum; numbers are not significantly different (from 78.5 to 79.7 adults). A lower mean number of adults is observed on spikelets of T. dicoccum (28.2 \ub1 1.2) and T. spelta (28.5 \ub1 2) with a longer mean developmental time, 96 \ub1 0.8 and 112.2 \ub1 3.2 days respectively. The shortest mean developmental time is observed on kernels of T. monococcum (54 \ub1 1.8). The highest mean number of adults of P. interpunctella is observed on kernels of T. dicoccum (71 \ub1 5.5) and of T. spelta (70 \ub1 2.2) with mean developmental times of 42 \ub1 0.8 and 36.7 \ub1 0.5 days respectively. Few individuals develop on T. dicoccum (5.2 \ub1 1.3) and T. spelta (2.2 \ub1 1.3) with mean developmental times of 59.2 \ub1 5.4 and 42.5 \ub1 0.6 days